Wtf?

[Jdog]

My cousin has a 20 gal tank in his smaller boat and he didn't even fill it up and after he took it back out of the water he noticed a gas smell, so he went to take the gas cap off and it shot gas up in the air, he blew out the overflow and he doesn't think it was clogged but it could of been, but the strange thing is he now has more gas in it then he did when he put gas in it, he said maybe after sitting in the sun it expanded. WTF?

He said gas was coming out of the drain in the back of the boat onto the street and headed to the sewer, Thank god nobody drove by and tossed a cig out the window, it would of got his jeep and the boat.

Any ideas?