It's so funny someone mentions that, because this game is very much like a Reality TV simulation (or a pop culture simulation) rather than a real life simulation, and it so happens that, during the first modern reality tv we had in my country, two contestants woohooed in the swimming pool xD
And aside from that anecdote, it's kind of a trope... so yeah, I think woohoo in any swimmable water should be an option. Swimming pools, lakes, ocean... I do not have Island Living yet so maybe it has the option? In any case, there's always the option to use the hot tub.
