SAN DIEGO -- Thousands of people on spring break are expected to launch rafts and inner tubes in Sail Bay this weekend for what is called "Floatopia."

In its second year, Floatopia is an event in which partiers take advantage of a loophole in the city's beach alcohol ban.

This Saturday, as many as 6,000 people have RSVPs to Floatopia, and the three things needed are a raft, some beer and a lot of friends.

On Labor Day weekend last year, Floatopia was launched as a way to exploit the city's beach drinking law.

Pacific Beach resident Meredith Stone said, "Oh absolutely, there's a bunch of drunken idiots out there and that's one of the reasons I stay away."

Stone said she doesn't have a problem with Floatopia, but like police and lifeguards, she does worry about safety.

During the last Floatopia event, lifeguards responded to several near drownings. This Saturday, 15 extra lifeguards will be ready and police are summoning extra officers.

"We will have the resources we need to take care of problems if they occur," said San Diego Police Department Capt. Chris Ball.

This Saturday's Floatopia will be the first big water event since the police department's Harbor Patrol disbanded. Coast Guard and lifeguard boats will pick up the slack while officers on the beach will deal with public drunkenness, littering and whatever else may happen.

The last Floatopia ended with two or three arrests, a dozen citations and numerous beer cans littering the shore. While some neighbors have complained about the event, others like Stone say live and let live.

"I mean, as long as people are abiding by the safety rules as best they can, there's no harm, no foul," said Stone.

The last Floatopia was an all-day event, but this Saturday's gathering may not last that long due to the expected low water temperatures.