Conditions on the north coast this week are forecasted to be fairly routine: NW swell 5-7ft, wind coming up to 25 knots during the day. The south swell that ruined vis a couple of weeks ago is gone, but it's still a dice roll. My guess is that vis on the north coast right now is better than at Monterey BW. Temps have been cold this year; was 48˚ at Ft Ross two weeks ago.
Gerstle is a nice, fairly easy dive. But north coast diving can be wild so if you are inexperienced or new there it's good to go with people who know the place. The major dicey part of diving there is walking in or out over the slimy rocks and rotten kelp. Just go slow. There can also be longshore currents and surge, and bull kelp can be annoying, which makes more reasons to go with experienced locals. Good dive plans include: swim out to the reserve boundary (yellow painted rocks) and set a heading right (180 - 200˚
or left (130 - 150˚
, drop in about 18' at the boundary and go until turn pressure. You might get to between 40 and 50' depth. Then take a reciprocal heading for about the same duration as your outbound leg, maybe a bit less, and when that time is up, reset your compass for 330˚ and just head right back up broadway to the beach. Vis usually gets bad enough halfway back into the cove that surfacing makes the most sense. If you run into a lot of palm kelp and rocky obstructions you have probably missed the cove or run into a shallow rockpile; surface, get your bearings and reset.
You will see big ling cod, cabezon, huge abalone, nudibranchs, fish eating anemone, sun stars (maybe a stimson star if you are lucky) and urchins. Go a bit deeper and you start seeing metrediums. The coraline algae is very pretty in the cove. Terrain is just a large boulder field with lots of crevasses, overhangs, walls, and crannies of all kinds. straight out of the cove in deeper water the bottom is mostly just slab rock with urchins and sunstars wandering around. There are a bunch of anchors out there scattered around. And on the left side there are a couple of fun structures to play around in.
Gerstle is a protected reserve, so there is no take within the boundary. If you hunt outside the boundary you have to surface before you get back into the cove and swim in with your catch.