One of the most-asked questions I get about scuba diving in Maine is how do you keep warm? It is a fair question and there is not really a simple answer. Cold water affects different people differently, some handle it better and longer than others. The key is to know when you are cooling down and make the turn in your dive and avoid becoming too cold or unresponsive.

Water temperatures in Maine depend upon the season. Ocean temps can range anywhere from mid-30 degrees F in the winter to 60 degrees at the height of summer. Most of our local dive club members pack their gear away when waters get into the 40s, although some will step up to the challenge if there is a nice sunny day with no wind.

Water temps are also different based on location. On one day in mid-April, the website reported the warmest ocean temp that day was off Richmond at 55 degrees F and the coldest off Eastport at 40.6 degrees F, a span of 14 degrees! Water temps differ with depth as well, the deeper you go, the colder the water.

At Beauchamp Point in Rockport, summer water temps near the surface can reach the balmy 60s, while 40 feet down they can be 10 to 15 degrees cooler. Temps are also affected by freshwater sources. The waters at Duck Trap Harbor are always a little chillier due to the cold waters of the river flowing out there.

So, what is a scuba diver to do? Option one is to not dive in Maine or New England waters. We actually have some members of the Aqua-Nut club who dive mostly on tropical or exotic vacations. In the tourism biz it is called destination diving. They are members who make use of the high school pool in the winter to keep up their scuba skills. Local diving does not have much allure for them.

While those exotic dives are indeed incredible, they don’t come around very often and can be quite costly. So, if you do want to dive a lot and you live in Maine, then local diving provides more economical and more frequent opportunities. But you have to deal with the colder water temps.

Option two is to use a dry suit. Scuba dry suits are rugged, expensive, and used by many divers. Some of our dive group swear by them and think those of us who dive wet here in Maine are crazy. So early on, I looked into them.

I had chances to try them out, a fellow diver tried to entice me into taking the Dry-Suit certification class. Meh, I was not that impressed. Getting into the darn thing was the first big challenge. I found that the neck seal was not my friend. It chafed and I certainly did not like that feeling of a constant pair of hands wrapped around my throat in a tight grip.

With dry suits you also have to keep track of things like the bubble, or the air that is in your suit around your body. One of your hoses to the tank can put air into the suit. This is a constant task to keep track of, especially as you descend. Otherwise, you might experience a squeeze, particularly in the wrong places…if you know what I mean.

As if this was not challenging enough, you also have to maintain proper body position in the water column. I learned that one of the certification skills you have to pass is to deal with air in your suit suddenly rushing to your feet and bringing you to the surface upside down in an uncontrolled ascent! Yikes!

Then there is price. You can find older, cheaper, used dry suits but they tend to leak or need constant repair. Pretty uncomfortable when you to expect to be dry under your suit, but a pin-leak soaks you and chills you down. Newer or custom-made suits do the trick but tend to cost four or five times as much as a good wetsuit.

Another drawback is that you tend to need more lead or weight for dry suit buoyancy than you would for a wetsuit. Many divers use an actual harness for their lead. With my bad knees, the idea of lugging even more lead around was a deal-breaker. For a variety of reasons, I decided dry suits were not for me.

Option three then is the wetsuit. It does just what the name says. It allows a layer of water into your suit, which is then trapped between your skin and the suit’s neoprene lining. This water layer can be a little shock at first, but quickly warms. Then you are good to go. While some don’t appreciate that initial shock, I think of it as a fair price compared to an out-of-control feet-first ascent!

For early and late season diving, I use my Bare 7 mm semi-dry wet suit, this was for an early April dive at Duck Trap Harbor. Note the front entry zipper across the chest and a hood. (Photo by Charles H. Lagerbom)

Wetsuits come in different layers of thickness from 3 mm to 7 or even 8 mm. Most wetsuit diving around Maine waters involves 5 mm or more. Most of our club’s wet divers tend to use 7 mm suits. Some are one-piece with hoods, others are two-piece. Some have hoods, some do not. This is all based on the diver’s preferences.

My older 7 mm semi-dry wetsuit for the summer months allows me to go with a 3 mm beanie, this was from our Ash Point dive at Owls Head in August. (From collection of Charles H. Lagerbom)

Then there are semi-dry wetsuits. I know, almost sounds like an oxymoron, a semi-dry wetsuit has cuffs at the hands and feet which more slowly lets water in to be trapped against your skin and warmed. You are still diving wet, but the water doesn’t get in as fast, which means you can stay warmer underwater longer.

Seven mm Farmer John style of wetsuit for a double protection of body core with a bib overall and step-in jacket. (Photo by Charles H. Lagerbom)

I started diving with a two-piece 7 mm wet suit called a farmer john, consisting of bib overalls and a jacket. In the old days, the jacket had a huge flap on the back with buttons to attach to the front that everyone called the beavertail. Today’s farmer johns have jackets that end in shorts you step into. This creates a double layer or 14 mm of neoprene over your body core.


Now my suit of choice for early or late in the dive season is a Bare 7 mm semi-dry wetsuit. It is one-piece with a hood, no neck seals or anything. It does a pretty good job of keeping me warm. The entry zipper goes across the chest from shoulder to shoulder. This way I can get into and out of it by myself. With back zippers, you need an assistant.

Once water temps get to the 50s, I tend to go with an older blue and gray 7 mm semi-dry that has no hood. It does have zips at the arms and legs for easier getting into and out of. With no hood, I am free to use my 3 mm beanie, as I do not like the neck constriction of a full hood with neck flaps. It can be a bit chillier with the beanie, but I prefer the freedom on my neck. Besides the orange and yellow beanie makes me easy to be spotted by fellow divers or recognizable in group pictures!

The orange and yellow beanie offers good visibility and identification with no neck constriction. (From collection of Charles H. Lagerbom)

I find that for me, cold water temperatures are toughest on my hands. This is what usually signals me to end a dive when fingers start to go numb. I use a variety of gloves, from 2 mm leather-palmed gloves if I need to tie things, write things, work with tools etc. Then I have 5mm Kevlar palmed gloves for more rugged work, but with less dexterity. Finally, I have 5mm semi-dry gloves which — like the suit — more slowly lets water in, lengthening the time before my hands get too cold.

One of the colder dives I did here in Maine was during the first week of December, we decided to go in off Pemaquid. It was a decent sunny day with air temps in the 40s. My dive buddy had a dry-suit and so let me choose when to turn (which means to signal and start heading back, finishing the dive). We were going along fine; the water temperature was 38 degrees F.

It was a great dive, visibility was incredible, although after a while, I noticed my regulator was loose in my mouth. My lips had kind of numbed out and could not hold the reg very well. My fingers were also starting to go — I could not tell if I was pushing the button on my GoPro or not. I made the turn signal and we headed back.

That was all well and good, but what made it such a cold dive was when we got out of the water. The day was still sunny, but a decent northerly wind had picked up. This quickly and thoroughly chilled me down. Already struggling with numb hands to get out of a wetsuit, doing so in such a wind made it even more challenging. I opened the door to my car, hoping it would provide something of a windbreak.

My wet hands were so stiff and cold, it was difficult to undo my buckles or unsnap things. I found it even tough to just turn the key in the car’s ignition to get the heater going! Later on, telling this to story my wife, she affirmed our club’s name of being the Aqua-Nuts and pointed out that 38 degrees F water was just six degrees from ice…Huh, I hadn’t thought of it that way!

Charles Lagerbom teaches AP US History at Belfast Area High School and lives in Northport.  He is author of “Whaling in Maine” and “Maine to Cape Horn,” available through


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