Here's some ideas...

JAMAICA
Be green, be unique, be an example to the rest of the world.
Lower pollution, create less noise, have safer waters, and attract more tourists.
Add spot: (3 sec clips of beaches with jet skis ripping by, obnoxiously loud, with blue smoke coming out the back, just missing swimmers / Cut to a peaceful Jamaica beach, two people in lounge chairs, drinking Red Stripe, watching whales swim by ) Announcer speaks,"Jamaica, feel the vibe".

OPERATORS
For every used jet ski buy 3 kayaks.
Rent the kayaks and triple your business.
Provide guided tours to increase employment.
Less fuel and maintenance equals more profits.

OWNERS
Buy a boat, they're much more fun.