Dry suit under gear

Bought a dry suit and now am looking for some advice on what to wear under it while fishing in the SF Bay. Thanks for any advice!

Go commando!!!

I think most people wear polyester base layers including myself.   Cotton is NOT recommended because it doesn't wick sweat away from your body although I can't confirm this.  Its easier to deal with over heat, you can open your dry suit temporarily or tug at the neck gasket.  There isn't much you can do about getting cold so keep a beenie or balaclava around in case the weather changes.   

You also may want to keep around a utility cup i.e. a piss cup.  Personally, I use a plastic Jack in the Box cup.  NCKA members will attest to the fact you may get a fish-on when doing #1. 

Depends how hard you paddle!

There are expensive liners from companies like Kokatat but I just go with 32 Degrees top + bottom (Costco used to sell these) as my baselayer and add more layers, all synthetic fabrics, during the winter months.

Depends how hard you paddle!

There are expensive liners from companies like Kokatat but I just go with 32 Degrees top + bottom (Costco used to sell these) as my baselayer and add more layers, all synthetic fabrics, during the winter months.

+1. I do exactly that.

Get a collection of polypro and pile underwear, pants, sweaters, jackets, and socks which you can layer up under your drysuit, and put on however many layers are appropriate based on the air and water temperature.  If there is a chance that you could end up in cold water for any period of time if you get dumped out of your kayak, you need to dress for the water temperature, not for the air temperature, even if that means that you need to spash water on your dry suit periodically to keep cool while you're kayaking.  I use the same polypro and pile clothing year-around for ice fishing, backcountry skiing, backpacking, hunting, and various other sports in addition to wearing it under my dry suits.

Acrylic sweaters are almost as good as polypro or pile in terms of not absorbing water.  This time of the year, stores are dumping their winter clothing, so you may be able to find some acrylic sweaters on sale real cheap.  Look for sweaters which have a lot of loft for warmth.  An advantage of round neck sweaters over pile jackets with high collars is that the round necks will fit smoothly under your neck gasket, and won't bunch up like the high collars on pile jackets.

When kayak fishing, it is often pretty chilly first thing in the morning, but pretty hot by the middle of the day.  Or a day which starts out calm and warm can change to cold, windy, and rainy conditions by the afternoon.  A good way to adjust your warmth when wearing a dry suit is by bringing a pile hat which fits under your sun or rain hat.  It takes up very little space in a dry bag inside your kayak, and you can quickly adjust how warm you feel by putting on or taking off the hat.  If I anticipate a big temperature change, I may wear a parka and/or a pile jacket over my dry suit in the morning, and then take it off and stuff it inside my kayak as the day warms up.  But be careful about wearing pile clothing over a dry suit, because if you get dumped out of your kayak it will soak up water and become heavy, which will make it harder for you to climb back into your kayak.

Don't ever wear anything cotton under a drysuit, or for any other outdoor activity.  Cotton absorbs a huge amount of water, which will conduct heat away from your body rapidly and make you cold.  And cotton dries out very slowly. See https://gizmodo.com/why-cotton-kills-a-technical-explanation-1688286083.

By comparison, after a day of kayak fishing or snorkeling and spear gunning in a dry suit, I frequently wear the polypro and pile clothing I was wearing under the dry suit on the drive home.  Any perspiration which accumulated in the clothing while I was wearing the dry suit will evaporate quickly out of the clothing.

Cotton kills...first thing my dad told when I was 10 when we hunted the backcountry in the fall. When I was in the Navy I wore silk underwear under my dry suit. It wicked sweat, was not overly hot so it was good when you didn't need heavy poly pro for colder weather. It also didn't stink after being worn all day. Poly pro is great stuff and I own a lot of it, but some other ideas to consider are merino wool base layers...first lite is just one company I recommend but there are a few. Another idea for cold weather fishing when water temps are cold would be layering with several types and maybe even fleece.  I love under armour and silk as a base layer than merino over the top. Wicks incredibly well, and is anti microbial. Just some ideas.

What pmmpete and Shrthrcrzy said.  I have three weights of base layers, all of them polypropylene, and can mix and match as suits me.  I get mine from Sierra Trading Post when it's on sale, but someone told me you can often find heavy Under Armour polypropylene fleece sweatshirts and sweatpants at Goodwill outlets to save money for thick base layers.

You don't dress for how much paddling you do!  Never!  You dress for how cold the water is otherwise you're in trouble if you happen to end up bobbing around in the ocean without your kayak.  The whole purpose of our immersion gear is to keep us warm IN THE WATER, for pity's sake.

To cool down in a drysuit, pour water on it.  You may need to do that every so often, but it cools you down rapidly.  Besides, a pee cup should have more than one use...

Have fun.  Stay safe.
 

The best advice on this thread is to dress for the water temp.

I wear a 7 mm farmerjohn under my drysuits.

Lots of good advice, but I'd add that polypropylene stinks to high heaven. I'd recommend "smart wool" instead. And pmmpete's comment about wearing a hat is exactly right, as your head acts like a radiator that can be used to adjust you comfort level without needing to strip off your drysuit and readjust your layering underneath.