Puget Sound

A day here is planned off a current table, not a boat schedule. Divers pick the smaller of the day's two exchanges, work out slack for that particular site, which can run well off the prediction at the nearest station, and time the entry so the water is still while they are on the bottom. That can mean a start at first light or a long wait through the afternoon. Kit goes on at the car, the walk in is over cobble or a boat ramp, and a two-tank day often means two different beaches.

The sound is a drowned glacial trench and the profile shows it: steep silt-and-cobble slopes falling away from a narrow shelf, broken by rock piles, pilings and dropped structure. Colour comes from invertebrates rather than coral, with sponge on the deeper rock, sea stars and tube worms over the boulders, and bull kelp in the shallows through summer. Sites divide roughly into city-edge parks, the steeper and quieter walls down Hood Canal, and harder-flushed water toward the north end.

Winter is worth more than the visibility gain. Sunset comes early, so a night dive can start straight after work, resident animals are easier to find in the dark, and the shallow squid runs fall in the same cold months; sites that look plain at midday change entirely after sunset. The trade-off is that all of it happens in dark green water. A good primary light belongs in the kit next to the drysuit, and that holds at noon in August as much as on a December evening.

It suits divers who like doing their own planning and do not mind being cold for a hobby. There is no resort structure to lean on: you own or rent gear, fill locally, read the tables and go, which makes it cheap to dive often and a straightforward place to build cold-water hours. Several of the better-known sites are no-take preserves, one or two sit behind private land where a shop handles access, and taking a giant Pacific octopus is banned outright at a list of designated dive sites. Critter hunters and macro shooters get the most from it; anyone after warm water and big pelagics should look elsewhere.