Summer's creeping closer, and if you're one of those ambitious types eyeing a triathlon — or just want to pretend you are while getting a killer workout — you're going to need somewhere to swim that isn't your bathtub.

Good news: San Francisco has one of the best open-water swim spots on the West Coast, and it won't cost you a dime.

Aquatic Park: The Go-To

Aquatic Park, nestled in that iconic horseshoe of piers near Fisherman's Wharf, is the consensus pick for triathlon training in the city. The pier structure creates natural baffles at water level that cut down on currents, making it about as forgiving as the San Francisco Bay gets. As one local swimmer put it, the setup "significantly cuts the currents" — which, if you've ever been caught in Bay chop, you know is no small thing.

You'll occasionally spot someone in a high-viz swim cap making the trek along the waterfront toward Crissy Field, but that's generally not advisable for most swimmers. Boat traffic — both recreational and small commercial — makes it a riskier proposition than it looks on a calm day.

The Pro Tips Nobody Tells You

The South End Rowing Club has published a solid guide on swimming Aquatic Park safely. Worth a read before your first plunge.

Here's the insider move: there are free showers at the park, but they're cold. (This is San Francisco — of course they are.) Both the South End Rowing Club and the Dolphin Club alternate days when the public can pay a small fee to use their lockers, showers, and — here's the real draw — their saunas. One local swimmer recommends checking out the saunas "at least once" as a post-swim reward. We'd say that's underselling it.

Not an Open-Water Person?

Fair enough. The Bay is cold, murky, and occasionally features marine life you'd rather not meet. Several gyms around the city offer pool access with a membership — a perfectly reasonable (and warmer) alternative for getting your laps in.

The bottom line? You don't need an expensive coaching program or a country club membership to train in this city. The Bay is right there, the infrastructure is free (or cheap), and the only barrier to entry is a wetsuit and some nerve. No government program required.