Can it be use to find the dive boat when you are underwater?
Miyuki S The H22PX would not be capable of locating your dive boat when you are underwater. You may get a distance reading if you were a few feet away likely you would not get a depth reading if you point the transducer towards the water surface.
STANLEY S If you need this to find the dive boat you have a problem of zero visibility. A great device to check depth,before you try to look at your depth gauge at the bottom. I have a habit of wondering how deep is that spot. Brought it to Hawaii ,but on a wreck at 80 feet ,75 ft visibility,what am I to point it at? In Cozumel at 130 wanted to point it all over to an endless depth,but have to safely keep with the group in fast moving currents. So a great item.If you need it to save your life, you have no common sense. Stan
RAY E i only used it on the surface to find depth to go diving.
HAL K Sorry to be unable to help you, but I only use the product to check water dephs.
BRAD D Sorry , haven't tried to