I’m taking the New Jersey boating safety course (required to operate a boat in NJ or NY). This entry in the student manual is particularly helpful:
Causes of Accidents / Striking a Submerged Object:
…Plain bad luck, as many times there is no way to see a submerged or partially submerged object before striking it.
Gee, thanks for the tip!
And this one:
Every boater should take a first aid course, including CPR and treatment of hypothermia. Being able to provide minimum first aid may prevent you from having to cut short your boating day.
Yeah, we wouldn’t want grandpa’s heart attack to ruin our boating day!
Here is the manual’s graphic for dangers when fishing or hunting from a boat (seriously):
