Many people come to Maui and go whale watching. Most people have a camera and want to get good pictures of the whale. Here are some tips.
1) dont hold the boat with one hand and take picture with the other. The vibration of the boat will come through and the photograph will be blurry.
2) Use a fast shutter speed. During the day you should get speeds of 1/250th, all the way through 1/2000th of a second. Fast speeds will frees the action and you can see water drops falling off the whales. One way to make sure your getting a fast speed is to set the camera on time or shutter priority and tell it which speed you want. The camera then will decide the F-stop.
3) Use a F-stop with good depth of field. I suggest F8-16. One way to do this is set camera on aperture control and select F8, 11 or 16 and then the camera will select the best shutter speed.
4) Set camera on continuous drive so you can take short bursts of photographs.
5) Use the fast memory cards if possible. The faster the read and write speed the better.
6) wear sun screen and have fun
See fine art whale photographs here