look up any word, like half chub:
 
1.
having sex with a girl doggy-style in the pool, in deep enough water that she has to keep paddling to stay afloat.
"I was in the pool with Catherine, and we ended up steamboating! The huffing and puffing when she ran out of breath only made it better!"
by Sinker23 May 23, 2006
 
2.
Like motor-boating... but with an asshole.
Bro, I was totally steamboating that girl all last night *high five*
by x3igh7 September 10, 2011
 
3.
A slow and deliberate face to breast oscillating motion.
Mark Twain is slowly steam boating his way through the golden girls.
by Samuel Clams. July 12, 2014