My left hand to Shiva, I saw a thread on a forum asking "How do you carry when you ride on your boat or Jet Ski?"
Look, slick, here's the thing: If you're on a boat, in the middle of the lake, you don't NEED to be carrying. Do you think that a street thug with a penchant for holding up the local liquor store is going to air-drop from a CH-47 and land on your boat and hold you up for your wallet before rolling off the gunwhale into the water and escaping with his SCUBA gear?
People like these idgits really annoy me.
How you should carry in 99.826% of your wakeful time: In a holster, on your hip, secured to a sturdy belt, and covered with your shirt.
If you think you're going to play Special Operator who Operates in Operations while you're swimming at the local watering hole, you're wrong. Quit trying to be something you're not.