I use Progressive and its not too expensive based on the coverage you get.
My 2012 RXT 260 costs $227/yr (see below)
My 2012 GTX 155 costs $221/yr
2012 Bombardier/SeaDoo RXT 260 (HIN: xxxxxxxxxxxxxxx)
Physical damage option:Actual Cash Value
Disappearing Deductibles:None
Coverages, Limits, Rate
Bodily Injury & Property Damage Liability:
Includes Fuel Spill Liability
$300,000 combined single limit$68.00
Medical Payments (Part 6): $5,000 each person$17.00
Comprehensive (Part 9):$500 deductible$69.00
Collision (Part 7):$500 deductible$40.00
Included with Comprehensive and (if purchased), Collision:Wreckage Removal, Marine Electronics - $500 deductible, Trailer - $250 deductible Included
Propulsion Plus®: No Coverage$0.00
Sign & Glide®: Selected$30.00
Coastal Navigation:75 Nautical Miles (included)$0.00
Replacement Cost Personal Effects:$1,000, $250 deductible$3.00
Roadside Assistance: Selected - Included
Total rate for this watercraft: $227.00
Shop around and report back once you find a good deal for you.