This is a short video that shows how I shoot video from a boat including some sample shots! I like shooting in very remote locations, I also like a flat bottom boat for minimal clearance under it (you can go to REAL shallow water), and also for setting a full size tripod on it, being able to smoothly pan is a big plus. I also shoot from a canoe but a flat bottom “John” boat works better as it’s less tippy. Use an electric motor driven off a deep cycle marine battery, this will add minimal vibration to the boat when it's running.
Setting the bubble (keeping horizon straight) for the tripod is important and tricky as a slight shift in your body will change the horizontal level in the boat. You need to put your one arm back on the motor like you are running it, then adjust the bubble of the tripod to keep it level when you are shooting. If your arm isn’t back like you are steering it, then the level will be off when you DO move your arm back!
Pick a very calm day (no wind or waves) and use an external monitor. When shooting another object in the water with you (like the canoe in the sample shots) practice and communicate with them for safety and also for getting the right distance and speed.
Finally water and gear don't mix!!! Be VERY careful not to flip over, make all moves as subtle as possible, with the tripod set up in it, the boat can be top heavy and more unstable, have help when you return to dock to take gear off boat first. If no one is around, try and put camera on dock first, then monitor and tripod, then you get out of boat last. This should minimize the chance of your gear going in the water.
Good luck and have fun!