We rented sea kayaks and paddled around Klein Bonaire (11k) and to/from (3k)...thats over 8 miles (!) in less than 3 hours!! Before we paddled back to Bonaire we snorkeled for a half hour or so. Snorkeling was worlds more relaxing than scuba diving, and I loved free diving down to a couple schools of fish (and to avoid the jelly fish at the surface).
On our way back to Bonaire we paddled fully into the wind-- there were whitecaps crashing against the bow of my kayak! It took us more than an hour, compared to the 15 minutes it took us to go to Klein Bonaire-- what an exhausting workout! We battled the wind, waves and fatiguing arms/shoulders/torso, adding up to one sore core, today.
I couldn't wait to finish that final stretch of paddling-- it was so grueling that I never want to see (sea) kayak ever again! ;) Not any time soon anyway. Overall, I felt a huge sense of accomplishment after my longest paddle ever.