Thanks guys for the comments.
This is a very broad beam kayak, which was chosen for stability more than speed. Cruises around 2.5 -3 mph, bit more if wide open. It is stable enough that some fisherman stand in them while fishing.
The same trolling motor fits on my jon boat, so I just move it to whichever boat I am using that day. Small battery for the kayak, versus much bigger for the jon boat. The setup allows me to go forward or backward as needed.
This trolling motor is GPS enabled, and can follow tracks, go to marked spots automatically, etc., but I am looking at an upgrade that adds an electronic compass to the GPS to allow holding headings more accurately. I want to be able to parallel the loons as they swim along, and maintain a constant position in relationship to the bird. It won't be perfect, but should improve my photo yield. Part of the fun of course is the tinkering! I have several friends who are engineers and do high end GPS work , so they are giving me advice and the details of such an implementation.
Because of what I am shooting, I am not out on windy days, or choppy water, so essentially flat bottom vessels are a good trade off, better stability for worse ride in rough water.
A vee hull boat definitely would be a better choice if in rougher water, and a gas motor is needed if you have to get back to shore in a hurry. When I shoot on larger inland lakes, I use a small gas motor, 5 hp to move me about more quickly to find the birds, and then use the silent trolling motor while taking pictures.
It really does change your photography in a major way when you can get out on the water. Even land animals such as deer seem to be less threatened by a approach from the water, as they don't see it as such a threat. Must be because we have no crocodiles in Michigan!
Randy