Dillard, Presiding Judge. This case involves consolidated appeals—Case Numbers A22A0797 and A22A0798—that come to us by way of granted interlocutory applications. In Case Number A22A0797, Tahir and Shannon Whitehead appeal from the trial court’s denial of their motion for summary judgment in a wrongful-death action brought by Ebony Green, as the parent of Tamira Green (a deceased minor) and administrator of the child’s estate. Specifically, the Whiteheads argue the trial court erred in (1) denying their motion for summary judgment when there were no genuine issues of material fact, and (2) denying their motion to strike testimony from Green’s expert witnesses. In Case Number A22A0798, White Pools, Inc. appeals from the trial court’s denial of its motion for summary judgment in the same action brought by Ebony Green. In doing so, White Pools—the company that built the Whiteheads’ pool—argues the trial court erred in denying its motion for summary judgment when (1) Green did not establish there were industry standards creating a duty to warn, educate, or inform a homeowner as to certain information; (2) there was no evidence that certain features of the Whiteheads’ pool caused Tamira’s injury; (3) the pool was not a product subject to strict liability; (4) there is no duty to warn of specific dangers associated with a product for which the dangers are open and obvious; (5) there was no evidence that a failure to warn more likely caused Tamira’s injuries; (6) it is not the manufacturer of one of the pool’s features; (7) it did not undertake to instruct the Whiteheads on general pool safety; and the trial court erred in admitting testimony from Green’s expert witnesses when (8) the experts were not properly qualified to give their opinions, and (9) the opinions were unreliable for a number of reasons. For the reasons set forth infra, we reverse in both cases. Viewed in the light most favorable to Green (i.e., the nonmovant),[1] the record shows that on July 3, 2017, the Whiteheads hosted an Independence Day party, during which they also celebrated the birthday of a family friend, Vanessa Davis. Davis—with the Whiteheads’ permission—invited some relatives to the party, including Rolinda and Bernard Bond, who did not know the Whiteheads and had never been to their home before. The Bonds brought their 4-year-old granddaughter, Tamira Green, to the party with her swimsuit in anticipation of there being some form of water activities for children. The Bonds were both aware that Tamira did not know how to swim, and when they arrived, they asked another relative, Jaida Davis, if Tamira could get into the Whiteheads’ pool with her and her baby niece. It is undisputed that Rolinda and Bernard also did not know how to swim and had no intention of getting into the pool. When Jaida agreed to watch Tamira, the Bonds began to socialize with other guests, with Rolinda moving into the house and Bernard remaining outside in a nearby seating area while Tamira sat beside Jaida on the edge of the pool. After a while, Rolinda saw Jaida come into the house and asked where Tamira was, to which Jaida responded that she did not know. Rolinda then began looking for her granddaughter throughout the party and its many activities, which included an inflatable bouncy house for children; but she could not find Tamira. Rolinda then noticed another guest carrying a small child out of the pool and realized it was granddaughter. Tragically, despite all best efforts (including CPR), being transported to a hospital,[2] and spending several days on life support, Tamira never regained consciousness and was pronounced dead on July 6, 2017. Bernard could not recall seeing Jaida leave the pool area or speaking with her again after initially asking her to watch Tamira, and he did not realize anything was amiss until his wife informed him that Tamira drowned. A video from a surveillance camera positioned over the Whiteheads’ backyard shows Jaida exit the pool with her baby niece and pause for several seconds within feet of Bernard to speak with him before leaving the area. And according to a police report filed after the incident, Jaida informed Bernard that she was leaving the pool so he would watch Tamira in her absence. In the surveillance video, Bernard is standing beside the pool when he is approached by Jaida. He then looks at Tamira, who is on or near the pool’s tanning shelf, before walking away. Within seconds of Bernard turning and walking away, Tamira fully enters the pool and slips beneath the water. Although she attempts to resurface—her arms below the water and face barely breaking through each time[3]—she travels further into the pool; and less than one minute later, she slips under the water for the last time. All of this occurs while other children play and swim around her, and no fewer than four adults sit just feet away from the pool’s edge, eating and socializing. But despite the large number of guests who were in the pool area (sitting along its edge or congregating nearby), Tamira was not discovered until 13 minutes after her struggle to resurface—when a swimmer’s leg bumped into her body at the bottom of the pool, at which point she was pulled from the water. An investigation by the local sheriff’s office concluded that Bernard “failed to supervis[e]” Tamira. Ebony Green—Tamira’s mother—told law enforcement that she did not wish to press charges against Bernard, her stepfather; but she thereafter filed a wrongful death action against the Whiteheads and White Pools—the company that built the Whiteheads’ pool[4]—on behalf of her daughter’s estate. Both the Whiteheads and White Pools proceeded to file motions for summary judgment and motions to strike testimony from Green’s experts. Following a hearing, the trial court denied the Whiteheads’ motion for summary judgment, concluding that genuine issues of material fact remained as to whether they breached a duty of care to warn guests of a hidden hazard—i.e., that certain features of their pool could obscure objects at the bottom, and whether they breached a duty they voluntarily assumed by announcing floatation devices for use but failing to identify non-swimmers and provide them with such protection. The court further concluded there were genuine issues of material fact as to causation and rejected the Whiteheads’ contention that the lack of supervision by the child’s grandparents was to blame when expert testimony suggested that, in the absence of the pool-design features selected by the Whiteheads, the child would have been noticed by other guests. Likewise, the trial court denied the Whiteheads and White Pools’s motions to strike the testimony of Green’s expert witnesses, Dr. Thomas Griffiths and Dr. Gerald Dworkin, as to the pool’s features, visibility, drowning risks, and applicable standards of care. The court rejected White Pools’s contention that the experts lacked proper qualifications to render their opinions. It also rejected the assertion that the experts’ opinions were unreliable. But as to both the Whiteheads and White Pools, the trial court granted certificates of immediate review. We then granted their applications for interlocutory appeal, and these consolidated appeals follow. Summary judgment is, of course, proper when “there is no genuine issue as to any material fact and the moving party is entitled to a judgment as a matter of law.”[5] Furthermore, a de novo standard of review “applies to an appeal from a grant or denial of summary judgment, and we view the evidence, and all reasonable conclusions and inferences drawn from it, in the light most favorable to the nonmovant.”[6] Finally, at the summary-judgment stage, we do not “resolve disputed facts, reconcile the issues, weigh the evidence, or determine its credibility, as those matters must be submitted to a jury for resolution.”[7] With these guiding principles in mind, we turn now to the enumerations of error in each appeal. 1. Case No. A22A0797 (a) For starters, the Whiteheads argue the trial court erred in denying their motion for summary judgment when there were no genuine issues of material fact as to whether they were negligent. We agree. The essential elements of a negligence claim are “the existence of a legal duty; breach of that duty; a causal connection between the defendant’s conduct and the plaintiff’s injury; and damages.”[8] As a result, we must first identify the duty of care the Whiteheads owed to Tamira, which is the threshold issue in causes of action for negligence.[9] As a social guest in the Whiteheads’ home, Tamira was a licensee.[10] And a property owner incurs liability for breaching a duty to a licensee “only for wilfully or wantonly allowing a dangerous static condition . . . to cause [her] injuries.”[11] In other words, under Georgia law, a property owner owes a licensee a duty not to wilfully and wantonly injure her, and the property owner cannot knowingly let a licensee run upon a hidden peril on the premises or wilfully cause her harm.[12] Additionally, “wanton conduct” has been defined as “that which is so reckless or so charged with indifference to the consequences as to be the equivalent in spirit to actual intent to do harm or inflict injury.”[13] But importantly, a property owner must actually know about and foresee a dangerous condition before a duty to protect arises.[14] Suffice it to say, the mere ownership of a swimming pool does not make a property owner liable for a licensee’s injuries. Indeed, a property owner is not an insurer of social guests, and the Whiteheads are not presumed to be negligent “merely because [Tamira] sustained [her] injury while rightfully on their premises.”[15] Further, it is well established that the existence of a swimming pool is open and obvious, and a pool is not a per se pitfall or mantrap.[16] Here, Green contends—and the trial court agreed—that there are genuine issues of material fact as to whether specific features of the Whiteheads’ pool constitute hidden perils about which they had a duty to warn their social guests. Specifically, Green points to the testimony of her two experts, who opined that the pool’s liner, tanning shelf, darkly colored interior, and waterfall features made it difficult for guests to notice Tamira at the bottom until 13 minutes after she slipped under the water. She also argues the trial court correctly concluded there are genuine issues of material fact as to whether the Whiteheads voluntarily assumed a duty to render services to another by their invitation to use floatation devices. As to whether the Whiteheads had a duty to warn social guests about specific features of their pool, a number of courts in other states have concluded that when a condition within a swimming pool is itself open and obvious (such as cloudy water, which can decrease visibility of people and objects), pool owners have no duty to warn of such conditions.[17] This is, of course, in stark contrast with conditions that are not open and obvious, such as pool drains with dangerous suction power[18] or pool depths that are difficult to decipher.[19] But regardless of whether the relevant pool features constituted a hidden hazard, Green is still be required to show the Whiteheads had knowledge of and could foresee the additional danger posed by such features;[20] but there is no such evidence in the record. Indeed, the Whiteheads testified they never had trouble seeing swimmers beneath the water of their pool with the features Green’s experts opined created a hidden danger of reduced visibility.[21] And although Green attempts to liken this case to those in which defective construction is alleged, as further discussed in Division 2 infra, there is no evidence the Whiteheads’ pool was in any way defectively constructed.[22] Instead, rather than suggest the pool or its features were defectively constructed or violated construction codes or building standards for residential pools, Green’s experts opined the pool builder should have warned the Whiteheads about its features. And it is undisputed the pool builder did not do this, which gives rise to some of Green’s claims against the pool builder, discussed infra. Thus, in light of the foregoing, there is no evidence the Whiteheads had—or should have had—knowledge that specific features of their pool were hidden perils.[23] There is also no evidence Tamira would have been discovered earlier if the Whiteheads had provided warnings to guests about the pool features. It is, then, mere speculation that any warnings by the Whiteheads—even if they had been required to give them—would have led to an earlier discovery of Tamira.[24] Indeed, there is no evidence the Bonds would have acted differently while supervising Tamira if they had been warned that particular features of the Whiteheads’ pool reduced visibility of swimmers.[25] Accordingly, the trial court erred in denying summary judgment to the Whiteheads on this claim.[26] (b) We likewise reject the contention that there is a genuine issue of material fact as to whether the Whiteheads “voluntarily assumed” a duty to protect Tamira and other guests, under Restatement (Second) of Torts §324A, when Shannon announced that floatation devices were available for children and non-swimmers and indicated where the devices could be found. That principle, as adopted by the Supreme Court of Georgia, provides that [o]ne who undertakes, gratuitously or for consideration, to render services to another which he should recognize as necessary for the protection of a third person or his things, is subject to liability to the third person for physical harm resulting from his failure to exercise reasonable care to protect his undertaking, if (a) his failure to exercise reasonable care increases the risk of such harm, or (b) he has undertaken to perform a duty owed by the other to the third person, or (c) the harm is suffered because of reliance of the other or the third person upon the undertaking.[27] And as our Supreme Court has recognized, Section 324A “[a]pplies only to the extent that the alleged negligence of the defendant exposes the injured person to a greater risk of harm than had existed previously.”[28] The announcement that flotation devices were available for use did not expose any guests to a greater risk of drowning than already existed by virtue of swimming in or congregating around a pool; and it cannot reasonably be construed as an undertaking to further warn guests about the risks of drowning in the pool.[29] For that matter, there is no indication that Shannon’s announcement induced the Bonds to seek a floatation device for their granddaughter. Needless to say, it would normally be “the duty of a parent or other adult having primary supervisory control over the child to see to it that a child would not be going into a place of obvious danger.”[30] After all, a swimming pool is, as a matter of law, an open and obvious danger.[31] To be sure, the facts of this case are undeniably tragic and heartbreaking. Even so, it is undisputed that Tamira’s grandfather (Bernard) was supposed to be supervising the child at the time of the incident, and he was unquestionably negligent in failing to do so.[32] So, given the foregoing facts (including the Bonds’ undisputed knowledge that Tamira could not swim), the Whiteheads cannot be held responsible for the death of Tamira,[33] and “[t]o hold otherwise would be to make [them] strictly liable for injuries to the child which resulted from a failure of the child’s [grandfather] to properly supervise her.”[34] Accordingly, for all these reasons, the trial court erred in denying the Whiteheads’ motion for summary judgment. (c) Because we reverse the trial court’s denial of summary judgment to the Whiteheads, we need not address their remaining enumerations of error as to the trial court’s denial of their motion to strike the testimony of Green’s expert witnesses. 2. Case No. A22A0798. In addition to alleging the Whiteheads were liable for negligence, Green also named White Pools as a defendant, asserting that the company was negligent in its design, installation, or construction of the pool, resulting in reduced visibility of a person in distress. In doing so, she brought claims for negligent construction and design;[35] negligent instruction to the Whiteheads regarding pool safety;[36] strict liability for defective design of the pool;[37] strict liability for a failure to warn of the pool’s unique features;[38] and strict liability for a manufacturing defect with regard to the pebble color used on the pool’s interior.[39] Once again, the trial court denied White Pools’s motion for summary judgment and motion to strike the testimony from Green’s expert witnesses, giving rise to this interlocutory appeal. (a) Failure to Prove Causation. White Pools contends the trial court erred in granting its motion for summary judgment on Green’s claims for negligent construction and design (Count 1),[40] strict liability–failure to warn (Count 3),[41] strict liability–design defect (the pool itself) (Count 2),[42] and strict liability–manufacturing defect (the pebble color) (Count 4),[43] because she failed to establish causation. As to each of these claims, we agree. (i) Negligent Construction and Design; Design Defect; Manufacturing Defect. As to strict liability, under OCGA § 51-1-11 (b) (1), [t]he manufacturer of any personal property sold as new property directly or through a dealer or any other person shall be liable in tort, irrespective of privity, to any natural person who may use consume, or reasonably be affected by the property and who suffers injury to his person or property because the property when sold by the manufacturer was not merchantable and reasonably suited to the use intended, and its condition when sold is the proximate cause of the injury sustained.[44] And to state a claim for strict liability, the plaintiff must show that “(1) the defendant was the manufacturer of the product; (2) the product, when sold, was not merchantable and reasonably suited to the use intended[;] and (3) the product’s defective condition proximately caused plaintiffs injury.”[45] Importantly, there are three general categories of product defects: “manufacturing defects, design defects, and marketing/packaging defects.”[46] Here, of course, Green made arguments regarding a design defect (as to the pool itself) and a manufacturing defect (as to the interior pebble coating). In design-defect cases, our Supreme Court has concluded the best approach is the risk-utility analysis, in which there is a “balancing [of] the risks inherent in a product design against the utility of the product so designed.”[47] So, the appropriate analysis “does not depend on the use of the product, as that may be narrowly or broadly defined, but rather includes the consideration of whether the defendant failed to adopt a reasonable alternative design which would have reduced the foreseeable risks of harm presented by the product.”[48] Importantly, because a manufacturer “may owe a design duty under Georgia’s productliability statute or under this State’s decisional law, a plaintiff injured by a defectively designed product can pursue a claim against a manufacturer under either a statutory strictliability theory or a decisionallaw negligence theory or both.”[49] And to prevail in a Georgia products liability action, whether based on negligence or strict liability, a plaintiff must show that “the proximate cause of the injury was a defect which existed when the product was sold.”[50] A proximate cause is that which, “in the natural and continuous sequence, unbroken by other causes, produces an event, and without which the event would not have occurred.”[51] As to a manufacturing defect, it is one in which “there was [a] flaw from the manufacturing process[,] not in the design or specifications of the product.”[52] And here, no expert testified that the pebbles in question were flawed—much less that they were flawed due to an issue in the manufacturing process. But even if we assumed Green presented such testimony, she would still need to establish that the manufacturing defect proximately caused Tamira’s injuries.[53] On these questions, Green presented the testimony of two expert witnesses,[54] Dr. Gerald Dworkin and Dr. Thomas Griffiths. And as to White Pools’s inclusion of the complained-of features in the Whiteheads’ pool (i.e., the tanning shelf, water features, and dark interior pebble color), Dworkin opined that if the pool had a lighter interior, “it would have been easier to observe Tamira while she was submerged below the surface of the pool” and “the probability of seeing Tamira submerged would have been greater than with a dark colored bottom.” But he agreed that, in contrast with commercial pools, there was no requirement that residential pools be built with a light interior color. He also could not say with a reasonable degree of certainty how much more likely it would have been for Tamira to be observed earlier with a lighter color interior because “it was a combination of surface agitation from the features, surface agitation from the people that were in the water, compounded with shadows, compounded with the dark colored bottom, all of which contributed to the inability to observe [Tamira] because of the lack of supervision that was provided by the Whiteheads.” As to the water features in the pool, he opined that if those features had been turned off, “the opportunity to observe” Tamira “would have been greater.” In addition to the features of the pool, Dworkin also testified that the people who were standing around the pool were distracted by their phones and conversations, which was also a contributing factor to the failure to notice Tamira in a timely manner. Ultimately, it was Dworkin’s opinion that because of these factors, it was “critical to . . . either prevent [Tamira] from going in the pool or if you are going to allow her to go in the pool, there needs to be certain safeguards put in place,” such as wearing a life jacket, having an adult within arm’s reach, having a lifeguard, or designating a water watcher. He opined that, “had those requirements been there, Tamira would not have drowned.” And the “biggest contributor was the lack of dedicated supervision of people in the water.” Finally, he agreed the Bonds had a shared responsibility in Tamira’s death and that an adult who brings a child to a commercial or residential swimming pool has “the ultimate responsibility of looking after that child and the safety of that child[.] As for Dr. Griffiths’s opinion regarding the pool and its features, he opined that the tanning shelf, dark-colored interior, and surface agitation created by the water features constituted “hidden hazards” within the Whiteheads’ pool. He agreed the features were open and obvious, but the hidden hazard was that those features could create a situation in which “a person who is on the bottom of the pool can be basically made to disappear from view.” It was his view that “the disturbance on the water and the dark-colored bottom of the [Whiteheads's] pool prevented the partygoers from seeing Tamira’s body[,]” though he conceded it was also possible these features may not have contributed at all. While Griffiths agreed that, “had the bottom of the pool been lightly colored and there had been no water features adding to the ripple effect of the surface,” Tamira’s body would have been visible to people in and around the pool, he qualified that response to specify that “it would have been easier if . . . some adults there were designated as pool watchers and were given the job to stand at the pool side and watch the people in the pool.” And he could not testify regarding the extent to which the rippling effect in the Whiteheads’ pool was caused by their water features as opposed to the movements made by other people in the pool when Tamira drowned. Nor could Griffiths testify how much more quickly Tamira would have been discovered if the water features had been turned off or if a lighter pebble color had been used for the pool interior. Nevertheless, he opined that it “would have been more likely” if the pool “had a light-colored bottom and if there were no water features . . . operating at the time of the . . . pool party, one of the many people in and around the pool would have discovered Tamira’s body within the first six minutes after she had gone underwater for the final time.” It was Griffiths’s “educated guess” that ripples in the water were “probably . . . the most significant blinding factor . . . ” because “ when someone is perfectly still and you have ripples on the surface, refraction makes it look like a person really is moving.” But again, Griffiths acknowledged that a number of factors beyond water features create ripples, including other people in the pool, objects in the pool, splashing in the pool, and the type of gutters used on a pool (of which the Whiteheads had a type that allowed for more ripples). Finally, like Dworkin, Griffiths agreed the primary responsibility for a child in and around a pool is with the person who brings the child to the pool, particularly when that person knows the child cannot swim. So, although there was testimony that the dark interior pebble color and water features contributed to an inability to see Tamira’s body submerged in the Whiteheads’ pool, the testimony that Tamira would have been noticed in the absence of those features was entirely speculative because there was no testimony anyone actually attempted to look for Tamira but never saw her submerged in the pool. Indeed, the experts repeatedly opined that White Pools should have warned the Whiteheads about the features and instructed them to employ a lifeguard for pool parties or designate an official “water watcher” who would be free from other distractions. Here, the opinion that Tamira would “more likely” have been discovered earlier in the absence of the pool’s water features and dark interior pebble color was dependent upon the speculation that somebody would have been looking for Tamira.[55] And when a party is relying on inferences to prove a point, “not only must those inferences tend in some proximate degree to establish the conclusion sought, but must also render less probable all inconsistent conclusions.”[56] This, the evidence does not do. In addition to the foregoing testimony, Griffiths testified there can be a failure to recognize a drowning victim due to “intrusions and distractions of secondary duties, which is a perfect fit for a pool party.” These distractions can include eating, speaking with other people, playing with friends, talking on the phone, texting, or anything else that pulls the person’s attention away from the water. All of those things, according to Griffiths, can create external distractions that can cause a person to not see a drowning victim submerged in the water or at the surface. Furthermore, “internal noise,” or a person’s inner thoughts, can also create a distraction that causes a person not to notice a drowning victim even when looking directly at the water. Lastly, Griffiths described “cognitive body blindness,” in which a person will actually see a drowning victim but does not believe what they are seeing. Ultimately, Griffiths testified that people being distracted by their own thoughts and activities, and the angle of the sun at the time in question, were all variables that contributed to Tamira being under the water “for some time and not being found,” but there was “no way” to know the percentage or extent to which those variables contributed to the delayed discovery. Nor could he differentiate between the many different variables that caused rippling in the pool. And because of these different variables, it was Griffiths’s opinion that White Pools should have told the Whiteheads to hire a lifeguard if they intended to host pool parties or, in the alternative, to outfit all non-swimmers in life jackets. Here, it is undisputed there was no lifeguard or designated “water watcher” at the party, nor is there any evidence Bernard ever attempted to lay eyes on Tamira in the 13 minutes before her body was discovered. Additionally, Rolinda testified that when she spotted Jaida inside without Tamira, she began to look for her granddaughter, but she did not testify to ever searching for Tamira in the pool and failing to spot her. Rolinda’s testimony instead was that she remembered “running to look for Tamira, calling her,” and that someone said to “check the bouncy house.” As a result, Rolinda checked the bouncy house and a basketball court before seeing Tamira’s body being carried from the pool. Accordingly, the suggestion that Tamira would have been discovered soon enough to save her life in the absence of the relevant features is entirely speculative because there is no indication the people who were most responsible for her well being—even according to the expert testimony—looked for her within the pool area during the time she was underwater.[57] Furthermore, neither Dworkin nor Griffiths believed White Pools acted unreasonably in terms of building and designing the pool with the options picked by the Whiteheads.[58] To the contrary, Dworkin testified that his opinion was not that White Pools should not have designed or built a pool containing the elements and features present in the Whiteheads’ pool, but rather that White Pools should have warned the Whiteheads about the pool’s features and the proper safety protocols to follow when hosting a pool party. And Griffiths testified that the interior color of the Whiteheads’ pool was “relatively common.” Additionally, he was aware of no warnings or prohibitions against the use of the pebble color on the interior of the Whiteheads’ pool,[59] the use of three or more water features, or the use of a tanning shelf. Griffiths also affirmatively testified that he had no conclusions or opinions about the “design, construction[,] or installations” within the pool. So, because Green’s experts provided no testimony suggesting that any potential negligent construction or design defect was the proximate cause of Tamira’s death, and any testimony they provided that the pool’s design or features contributed to her death was mere speculation, the trial court erred in failing to grant summary judgment on these claims as well. (ii) Failure to Warn. White Pools further contends the trial court erred in denying its motion for summary judgment as to Green’s claim for failure to warn the Whiteheads about the pool’s features because, again, she failed to establish that the failure to warn proximately caused Tamira’s injuries. Again, we agree. In failure-to-warn cases, the duty to warn arises “whenever the manufacturer knows or reasonably should know of the danger arising from the use of its product.”[60] Nevertheless, proximate causation is “a necessary element of a failure to warn claim.”
