My family and I were enjoying a beautiful day in S.D. near Sea World (on the Ocean side near an amusement park) when off in the distance we heard thunder and saw lightning. The lifeguards told everyone to
"get out of the water and off of the beach, head for cover". We did!
About 10 minutes later this T-storm came right over us as we took cover in the outdoor bathrooms. Women in mens, men in womens, cats playing with dogs it it was crazy. I later learned that's not even a good place to go. I managed a peak out toward the parking lot and saw lighting strike horizontally just over the top of the cars all the way across the lot. The hair was standing up on the back of my neck. Not sure if it was from electricity or fear but judging by the stains in my shorts, I'm guessing the latter.
So, long story short... I'm guessing they said get out of the water for a reason. With scupper holes and being surrounded by H2o, whether in plastic or not I would GTFO.