Thanks for commenting, everybody.
John - it was definitely the ship spooking them. Every so often you'd see a school of them all taking off at once, sailing for a bit through the air.
I definitely had a great time on this vacation with my wife and two kids, my son who is just out of high school and headed to college this fall, majoring in Bioinformatics (look it up) and my daughter who is entering senior year in engineering college. Having adult kids made it refreshingly different than previous cruise vacations. We ziplined, swam with the dolphins, tubed down a river in Jamaica, etc. so were pretty busy. Oh...we ate alot too :P.
Great photography is largely a matter of one's perspective, both visually and mentally.