A speed boat tour in San Juan typically means jumping on a small open boat that zips around the harbor, past the old city walls, and out to nearby cays or mangroves. Expect 45-90 minutes of loud engine noise, wind in your face, and decent views of the forts and skyline. It's fun if you like being on the water and want a quick thrill, but it's not a relaxing sail—it's bouncy, often wet, and the guide's narration is usually basic. You'll see some nice scenery and get a few photo ops, but don't expect deep marine biology or deserted beaches.
Best time is December through April when the trade winds are steadier and the sea is calmer. Summer and fall can be sweltering with a higher chance of afternoon rain and rougher rides. Expect to pay around $35-65 per person depending on tour length, group size, and whether it includes a quick swim stop or drinks. Private charters run significantly more.
Tip: Pick a smaller morning tour when the water is usually flatter and the light is better for photos. Skip the ones that promise 'snorkeling' unless you're told the gear is decent and the spot is actually good—many just stop in murky water near the harbor. Bring a waterproof bag for your phone and a light jacket; it gets surprisingly cool at speed.