Hello, we have a 798 on order, should be here shortly. We'll be mounting it to a kayak, and we're wondering if there was any danger to a scuba diver below. We have 3-4 people usually with us, diving off the yaks. Some on the surface, some below. Is there any danger to the divers in 20-45 ft of water if someone on the surface is using the unit? Could we be around near them looking at other things with the unit, while they are below us. (and maybe seeing what we look like)