In the life raft with Hiro are: Vic (a sniper), Eliot (the skipper of the Kowloon), and "Fisheye" (the man with the glass eye).
Fisheye has a large black suitcase with him. A cord trails from it into the water, where whatever is attached is bubbling beneath the water's surface.
In conversation, it comes out that Fisheye has been sent to extract Y.T at Uncle Enzo's orders. Their first plan—a hostage exchange—got screwed up when the Russians got away.
They're stuck on the lifeboat for a couple days. Fisheye reads the manual to something; Eliot looks at the open sea with his binoculars.
Hiro uses his portable computer to code. He has access to the bit of Snow Crash that the Clint who'd tried to infect him in The Black Sun dropped, so Hiro codes around it (because looking at it might kill him).
If Snow Crash is a virus, what Hiro's writing up is kind of like medicine. He calls it Snow Scan, and it's a program that will protect Hiro's computer (and Hiro himself) from exposure to Snow Crash. Sweet.
He also mucks around with making himself an invisible avatar (hard to do unless you're a pro) and updating his motorcycle software. Might as well, since all he has on his hands is time.