On another site that I hang out on has a thread devoted to stories about deaths involving RC boats including these two. It's unfortunate that it has to be done but it makes people aware of what can happen. One lake that I used to run at has had several drownings due to people not knowing what lies beneath the surface. One was found only 20 feet from shore in 5 feet of water, more than likely entangled in the weeds.
I was surpised at the one who drowned in Florida from hypothermia as you'd think that the water down there would be warm enough to where that wouldn't happen.
Offshore is a class of boats where they have the scale-like appearance of the big boats. They also race in a variation of the standard oval course, an "M" shape so there's a left turn in every lap. Go into
www.impba.net and there's a schematic on the course lay-out in the rulebook section.