Hypothermia and sailing

The water temperature in Brenton Cove in the winter can regularly get below 40 degrees. Just ask any Laser sailor from Fleet 413, or from March on, any high school sailor. Add in 15 knots of wind in 35 to 40-degree air temperature and the combination certainly focuses the mind on paying attention to the conditions. This attention is elevated to some high number exponent when one has the care of a dozen or so teenagers, someone else’s delight of life. Such is the life of a high school sailing coach in the Northeast.

Accordingly, over the years I have tried to make myself aware of issues surrounding hypothermia. I carry with me a thermometer and regularly take the temperature of the water in the cove, and the air temperature if needed. As of this writing, mid-May, the water temperature in the cove is 54 degrees.

Several years ago, I was the master of a 65-foot cruising boat. At one point the owner was grumbling about the cold “hot” water. My first action was in fact to get a bucket and thermometer and go and measure the temperature, of just the hot water, not mixed with any cold. I ran the tap up for a minute, feeling it with my hand all the while, as we do. When it felt like it was going to get no hotter, and felt “OK,” not “hot” but about the temperature of say a back country motel in winter, I captured some in the bucket and introduced the thermometer. The water was 90 degrees. As will be noted later, 90 is OK, but not great, by the standards of the owner of a 65-foot custom boat.

One of the great advantages of living in Newport is having one’s morning coffee at Cru Café, off Bellevue Ave. Here one can invariably run into any of Newport’s cast of characters in the sailing game and it is where I do most of my Women on the Water interviews. One morning in late April I ran into a mate, one Jeff Clarke. Jeff is an interesting character as befits his place in the Newport sailing scene. A former Marine, former Newport cop and now a commercial diver, including bottom washing. It was in this last role that our discussion kicked off this particular morning. He has a collection of mates who are Navy divers based at the Newport Navy Station and they had called him to ask about staying warm in their diving drysuits. Their issue was the cold outside surface of the drysuit transmitting the cold through the material to the inside of the suit, and they wondered how much and what sort of insulation clothing Jeff wears when he is working. Such a question piqued my interest, because it is a near photocopy of the situation with high school sailing. My sailors on The Prout School team wear drysuits but many of them insist on wearing cotton under their suits, despite my admonitions to not do so.

Jeff picked up a thread we had already going from our last coffee gam of a school in southern Mass calling him and asking about a seminar in cold water sailing, for their sailing team. At that time we spoke for half an hour on many aspects of the issue.

One of the ideas we tossed around was to construct a short gathering, a baby symposium, on the topic. We would gather some language, a few bullet points concerning Hypothermia, readily understandable to a group of 15-18 year-old sailors, even the new ones.

Jeff would cover this material in say 15-20 minutes on the beach. We would have had a mark placed say 20-30 yards off the beach-This drill, in the coffee discussion, was to be conducted at the public beach that is on the grounds of Fort Adams, at the south end. Jeff would corral a couple of his mates skilled in operating in cold water as helpers and guards and to place the mark. I would drive the RIB, standing by. The kids would be invited to swim to the mark and back.

This would do a few things:

a) Demonstrate their swimming ability.

b) Demonstrate how hard swimming with a dinghy life jacket really is.

c) Exhaust them to some degree.

d) Give them a sense of what “cold water” means.

e) This latter would give them the experience to not be too completely wigged out the first time they capsize.

I think we can all agree that the first time you try and do something at sea, ought not to be when some positive action is REALLY required, thus the MOB drills and the rest of the planning and practice sailing, particularly racing, uses.

A bit of digging in the World Sailing site tells me there is a brief reference to cold water in of the Offshore Regs that addresses Cold Water Sailing/Hypothermia. What is there comes under the First Aid section. There are four pages dedicated to Hypothermia in the Special Offshore Regs, appendix “J”. Pages 52 to 55, in the current Offshore Special Regs book (or at least in the PDF on the WS site). Like much of the information in this Bible of Offshore Racing, the appendix is a broad overview of action to take as needed. Interestingly there is no actual definition of Hypothermia, and the third paragraph suggests that avoiding Hypothermia, even in mild cases, can help you keep a competitive edge.

A dive into Dr’s. Google and Wikipedia suggests a definition of Hypothermia is: A condition in humans where the core body temperature falls below 95 degrees F.

Contrasted with a human’s “normal” body temperature of 97.7 to 99.5, one’s core temperature has diminished by roughly three to five degrees when in a hypothermic state. Great, the technique for measuring core body temperature is not readily executable in the cabin of a boat bouncing around at sea, so proceed to the visual cues. For “Mild” Hypothermia, impaired judgment, shivering, and fast heart rate are visual or readily discerned indicators.

I reckon anyone reading this essay and who races in the Northeast has sailed a Block Island Race where it was “bloody freezin’.” This is of course due to the water temp on the Sound and the area around Block Island being still cold from the winter. At night the air temp will be hugely impacted by the water temp and so sitting on deck, even if it is not particularly windy and wet, will be cold.

There are some good graphs and similar media available, commonly from kayak sites, one of which I reproduce below, pinched from and gratefully acknowledged from US Kayak.



One of the common questions asked by the high school sailors in my care, particularly the skilled and experienced ones as the air temperature warms up in May, is, “When we can we wear spray tops”? (In lieu of drysuits). One of the difficulties with answering this question is the new, first-time sailors. In the middle of May, this question is put to me more regularly by the sailors.

The following is an email I sent to the parents, in particular the families of the new recruits, who are by and large all new to sailing.



As the weather warms up, the annual question from the kids is, “When can we stop wearing drysuits?” From my perspective the things I think about when answering this question are, in no particular order:

• The skills of each sailor, roughly translated to mean their abilities to not capsize.

• The temperature of the water in the cove. It might be just at 50 degrees F now.

• The wind conditions, 5 knots or 20 knots of wind.

• Sea state, wave size.

• The clothing they have, typically the experienced sailors compete in the summer and so have a “summer kit.”

• The details of such a summer kit are not germane, other than it is about another half a boat unit (Commonly agreed in the trade to be $1,000).

• And of course, the variations amongst each sailor to withstand cold water.

• Just coz it is a nice sunny day does not negate the impact of cold water and Hypothermia.

So, to the issue of your new sailors not wearing drysuits. And of you, parents, not having to go to the boat shop and break out another half unit on new kit.



1. Tell your sailor the need to keep wearing their drysuit. That is possible but they will on some days get too hot, and since (despite my admonitions) they don’t drink enough water anyway, they will likely, or it is possible they will get overheated. And if they do drink, drysuits are not the easiest garments from which to escape to go to the bathroom, especially when on the water. I’d say a bathroom run, from the docks and back is minimum 8-10 minutes, if dressed in a drysuit, life jacket, pinnie and otherwise ready to get in a boat.


2. Cobble together something from their existing sports/wardrobe kit. Tights are popular, esp. amongst the girls. And fleecy tops too…NOT COTTON. The “technical shirts,” those that “wick,” are good to wear close to skin.. Some kind of light nylon “spray” (also rain) top works, too.


3. A wise shipmate of mine once observed, “If you’re going to eat a horse, don’t stop at the tail. If your kids like sailing, and you are good with them having fun sailing, and particularly if they and you are going to have them sailing in the summer, then go for it and set them up with a full on summer sailing kit. The experienced sailors are the ones to ask about options, all of which are available at the usual places, Team One, Zim and so on.


One wild card in this issue I am sensitive to is:

Being the standout as a teenager.

If all the other kids are in summer kit (different clothes/uniform) and you are not, in some sports this might create a tension line. I have never found this or any similar peer pressure sensitivities to be apparent in Prout Sailing Teams, but I know such psychology exists in a teenager’s world.


From my research:

In 40°to 50° F degree water, loss of dexterity (fingers with no protective apparel) under five minutes. When the kids capsize I give them two attempts or five minutes to right the boat, after which I put them in the RIB and get the boat up some other way. (I carry hand warmers in my boat kit, esp. in the early days.)


In 40 degree air temp and 20 mph wind (conditions generally not unreasonable for sailing, particularly the skilled sailors) the wind chill equals 30 degrees F and after 30 minutes at 30 frostbite can begin.

None of the above calculations consider exhaustion, fear and so on.




Now interestingly and timely as it happens, yesterday, Monday 13 May we, the Prout Crusaders, sailed in the cove. The day was sunny and nice, the water temp 54 degrees, air temp mid-60s. The Veteran sailors all elected to sail in their spray tops, a catchall phrase indicating some combination of lightweight pants or thin wetsuit skins, a layer or two of fleecy things and a top similar to the pants. But primarily, no drysuits. But it was blowing, perhaps around 20 certainly so further north towards the south tip of Goat Island. The Rookies wore their drysuits.

We first reached down to The Ocean Race docks, the kids being excited to see these monsters. We did a couple of fly-by’s outside the blocked off basin then reached over to the Goat Island Green bell. After a few drills, perhaps 45 minutes or so in a gusty and fresh sou’wester, (read getting wet) one of the more experienced and capable sailors came up to me and asked if he could go in and change into his drysuit, from his spray top. I allowed that he could, all the while suppressing a chuckle of “I told you so.” I had the other boats sail up to the dock to take a break and bail the boats while he changed.

I walked along the docks to see how everyone was. One of the other sailors reported that she was uneasy and felt the conditions were right at the limit of her skill, confidence, and weight limits. She is not particularly big or tall. I regularly tell the kids any time we are sailing that they must tell me in situations like this, so I of course assented to her request to withdraw.

So where does this leave me, other than “This crop of kids is bright, self-aware, and thoughtful.” The last time I did the full Safety-at-Sea seminar, I cannot remember any discussion at all, let alone a breakout, in-depth discussion of Hypothermia. After pitching this story to Ben and Zep and getting their assent to the piece, I did a bit more shower temp testing. I found that:

a. A HOT shower is about 100 degrees. To me that’s when you need to start mixing cold water into the flow. A water temperature one would expect in a “good” hotel.

b. 90 degrees, the temp the owner of the 65-footer was upset about, was OK. I could have a 10 to 15-minute shower in this temperature.

c. 80 degrees “felt cool” starting towards cold, a cheap motel in the backwoods temperature. Doable, but not ideal.

d. 70 degrees felt cold. “I need it hotter” kind of thinking. Again, sort of doable but really fast.

Compare these temperatures with the local waters. I did a review of the NOAA data buoys around the Northeast after this shower test. Certainly, it is Mid-May, call it early season, or not yet launched for many sailors, but boats are out sailing. The IC37s are practicing already. American YC has had their Spring Regatta. The Twenty Hundred Club had their first regatta last Saturday. The VX Ones are out on Monday nights. On the Sound, The Edlu and Block Island Race are approaching. The season has begun.

The water temperatures around the WindCheck region in mid-May were all under 60 degrees including on the Sound. Narragansett Bay was 57, and most of the readings either offshore or inshore, Nantucket Sound for instance, were all very close to this temperature.

Consulting the sea kayak information, I see for this temperature:

• Between 50-60 degrees, loss of dexterity, with no protective clothing (I read this as neoprene gloves), is 10-15 minutes.

• Exhaustion or unconsciousness kicks in at 1-2 hours.

• Expected time of survival is 1-6 hours. And all this is with a drysuit and fleece undergarments, OR wetsuit and booties.

The disclaimer on this graph reads variously, “Drysuit or wetsuit is recommended. This is a basic GUIDE…if paddlers are inexperienced or conditions are rough, more clothing is recommended.” I don’t know anyone up here who sails aboard racing yachts in a wetsuit or drysuit. Do you?

Prior to writing this essay I reread the Incident Report on the Morgan of Marietta MOB episode in the 2022 Newport Bermuda Race. One of the facts found from data collected aboard the boat was the water temp at the incident site was 73 degrees.

When we look at the beach temperatures, we see 73 and think great, let’s go swimming. OK, now go home and set the shower to 73 degrees and stay under it for 30 minutes. Send a letter to Zep, reporting how long you could stand it.


This NOAA Wind Chill Chart graphs frostbite times by factoring air temperature and wind velocity. If you’re sailing in cold water and your skin’s wet because you left your drysuit ashore, you’ll be shivering much sooner…and cold ain’t cool.


The point here? I reckon more work, at all levels of sailing, ought to be put into Hypothermia discussion and instruction on how to recognize and address it, and in any event such research should be undertaken by the owner contemplating offshore yacht racing. Happy sailing season,

Coop ■