Wondering the same thing. I read the article 3 times trying to figure out where the friends where during this fiasco.

I know of some people that like to go canoeing / on a kayak alone. One of my brothers has gone windsurfing alone.

I guess this guy went Jet-Skiing alone? I wouldn't do it, but as mentioned, several people like water sports enough to do them on their own.

I believe the article specifically states that he was jet skiing with friends...

You're right:

" he was out jet skiing with friends on an inlet near the airport and had a mishap"

"Casillo’s adventure began at a Rosedale watering hole, where he was hanging out with friends when they decided to go out racing their watercraft.

But Casillo’s ride broke down in the dark waters of Jamaica Bay at around 7:45 p.m. — and his pals didn’t notice they had left Casillo behind.

With his craft taking on water, he called Cowan in a panic. “He said, ‘I’m stuck!’ and told me to call his friend Albert to come out and tow him in,” Cowan, 28, recalled. But help didn’t come, and the stranded Casillo swam three miles toward the only thing he could see — the lights of Runway 4-Left, which sticks out into the bay.

Read more: http://www.nypost.com/p/news/local/queens/beach_of_security_... "

I'd guess they'd all been drinking.