Drysuit or 7 mm wetsuit for diving San Diego?
Updated September 2026 · Marissa Charters, San Diego
Either works. San Diego water at depth runs 50 to 52°F most of the year, 46 to 48°F in February and March, and 55 to 58°F from August through October. A 7 mm wetsuit with hood, gloves and boots is the minimum we take you out in. A drysuit is the better answer if you dive here often, dive in winter, or are cold on the second dive.
What the water does to you
The numbers first, because they decide everything else.
| Month | Water at depth |
|---|---|
| February and March | 46 to 48°F |
| Most of the year | 50 to 52°F |
| August through October | 55 to 58°F |
Those are bottom temperatures on our sites, not the surface reading on a beach app. On a Wreck Alley day you spend most of two dives between 60 and 100 feet on the Yukon and the Ruby E. In the Point Loma kelp you are shallower but often longer. In either case the cold has an hour or so to work on you per dive, then a surface interval on an open boat, then it starts again.
Nothing about a tropical 3 mm carries over. Divers who arrive from warm water with the suit they own are the divers we end up talking to on the dock.
The case for the 7 mm wetsuit
A 7 mm suit works in San Diego, and most divers on our boat wear one. Roughly six in ten of our regulars dive wet. It is the cheaper choice by a wide margin, it needs no extra training, and rental shops stock it.
Its limits are physical. Neoprene is foam, and foam compresses. At the Yukon's decks, 65 to 75 feet, your 7 mm is thinner and less warm than it was at the surface, and it has lost buoyancy at the same time, which is why weighting a thick wetsuit takes practice. Then you climb out wet. The wind across Mission Bay on the way to the second site does the rest, and your second dive starts colder than your first ended.
If you go wet, go all the way. Hood, gloves and boots are not optional here. A hooded vest under the suit adds a layer over your core and seals the neck, and it is the single cheapest upgrade a cold wetsuit diver can make. A heated vest is the next step for people who love their wetsuit and hate the second dive.
The case for the drysuit
A drysuit keeps the water off you. Warmth comes from what you wear underneath, which you change with the season: light undergarments in October, heavy ones in March. You climb out dry, drink the hot tea and start the second dive as warm as the first. For divers who come out with us monthly, or who dive December through April, that is the whole argument.
The costs are real. A drysuit and undergarments run several times the price of a wetsuit. You need training in one, because the air inside the suit is a second buoyancy system and it needs managing on descent and ascent. We take your word on the card, and the trip listing says so: a drysuit if you are trained in one. You will carry more lead than in a wetsuit, and the suit needs looking after, seals and zipper especially. A drysuit you have not dived in a year is not the suit to relearn on the Yukon.
About four in ten of our regulars dive dry, and the share climbs in winter.
Which one, plainly
- You dive San Diego a few times a year and own a 7 mm. Dive it. Add a hooded vest. Pick August through October if you have the choice.
- You will dive here monthly, or in winter. Get drysuit trained and dive dry. The second dive is where you will feel the difference.
- You are visiting from warm water. Rent a 7 mm with hood, gloves and boots. Do not rent a drysuit for your first cold-water dive unless you are already trained in one.
- You get cold easily in any suit. Drysuit, and heavier undergarments than you think you need.
Whichever you wear, thick neoprene or a bag of air changes your trim, and in the kelp sloppy buoyancy means entanglement. If the suit is new to you, a kelp day before a wreck day is the order to book them in.
What we provide and what we do not
Your ticket covers AL80 tanks, air fills and weights, along with hot tea, coffee and cocoa and warm packs for the surface interval. We do not carry rental suits or gear on the boat. Rentals are arranged through House of Scuba with pickup and drop off, roughly $57 to $89 plus $20 for the pickup, and they need at least three days' notice and your sizes.
Weighting the suit you chose
A starting point on one of our AL80s is about ten percent of your body weight plus roughly six pounds, then adjust from there. A 7 mm needs more than a 3 mm, a drysuit more still, and the first dive of a trip in a new suit should be a check dive, not the Yukon's sand at 102 feet. Weights are on the boat, so bring your best guess and change it at the surface interval.
Booking with the right suit
The trip listing states the certification for the day and the kit expectation with it. If you are unsure whether your suit or your weighting is ready for a given site, text Capt Lora at (619) 757-3280 before you book. Boarding is 8:00 am at Mission Bay Sports Center, 1010 Santa Clara Place, San Diego.