I’ll get right to the point here- photographing from a boat isn’t easy
Sooner or later we all get the opportunity to photograph from a boat. In many cases it is the only way to get a good picture. In my career I have photographed whales (a lot), seals, sea lions, dolphins, penguins, gulls, albatrosses, jellyfish, commercial fishing boats, sailboats, glaciers, black & grizzly bears, ice bergs, orcas, sea otters, bald eagles, wolves and lots of landscapes from a boat. Here are a few things you must do to get your best shots:
Choose the best boat for access and photography. This is the most important tip I can give you. If you are on an inferior boat no matter what you do photographically it won’t be enough. the best boats for photography are small, completely open with all sides accessible and with a captain that listens to your desires. Too many times I have seen serious photographers too far away, shooting through tiny windows, out at the wrong time of day and crowded with lots of non-photographers. Do your homework and find the smallest, most private boat you can even if it means spending a few more dollars.
Shoot a lot. When you are on the water everything is moving so it is nearly impossible to keep your autofocus points on your subject. It is hard enough just to keep your subject in the viewfinder! So shoot in bursts of 5-8 shots, don’t crop too closely and hope for the best.
Use the smallest acceptable depth of field to get the fast possible shutter speed. This means shooting in aperture priority with a pretty high ISO.
Go out when there is blue sky so the water is blue. On cloudy days the water is gray and it is not nearly as pretty.
Get as low as you can to the water to get the closest to the animals eye level. I know this sounds silly but the difference in the photo is striking.