If it is one of the bigger cruise ships, you can shoot with a tripod and not worry over vibration issues. Most of the Alaskan cruises go close enough to shore that you can get some great shots in the early morning or late evening right from the deck. I always go down to the lowest level I can get to and still have a clear view both out and upward. I opted for the Nikkor 80-400 instead of the Tamzooka after shooting one for a day. For me, older toot that I am, carrying that beast and a gimbaled head heavy duty tripod, carbon fiber or not is just way beyond my endurance. If I want more distance, I use the Nikkor 1.4 tele-extender which gets me to 550mm at f/8.
This was made on the Allure of the Seas, 11:00PM, moving at 18 knots in 5 foot seas, 2 second exposure.