Sharkskin chillproof under membrane drysuit in 19C water - what can I expect?

[Divectionist]

Hi there

A lifelong wetsuit diver, I will soon take delivery of my custom seaskin membrane drysuit. Took a few months but it is coming.

Now, I have a Sharkskin chillproof long sleeve, usually worn under my 5mm wetsuit, that I consider wearing as an undergarment on my drysuit test-out dive. The ocean surface temperature is currently 19-20 degrees, which is the lowest all year (I am in Australia).

All personal temperature sensitivity variations aside - I am basically wondering whether I should expect the Sharkskin long sleeve to be adequate in that membrane suit going into approx. 19 degree water for a 60-90min long dive to get familiar with the suit. Ideally I would purchase the chillproof pants and have that as my set of undergarments, unless I really need something more substantial.

Am I in the ballpark with this, or should I go shopping for something else right away?

Thanks in advance!

 

[Zef]

I don't think your sharkskin will provide much insulation at all but you may not need much. You mentioned the surface temp was 20c but what is the temp at the average depth you will be diving at. You may find that your sharkskin is enough for you or you may get chilled and abort your dive. It is all very personal so dive it and see.

I switched back to diving my wetsuit for this season because the thin fleece undergarment I was using was not sufficient to keep me from becoming chilled halfway through my dives and my dive partners who were wearing wetsuits just seemed more comfortable given the water temps @ 15-18 degrees.

The problem for me was that we had an exceptionally warm spring season here which made wearing a layer thick enough to provide insulation at depth, unbearable while gearing up and getting in. I purchased a used semi-dry this year for those season transitions where the water temp is not quite warm enough for my 5mm wetsuit but the air temp is too warm to dress out in insulation and drysuit.

Now that autumn has arrived, it is cool enough out that I will use the semi-dry again, and in about a month or so I will dust off and start using my drysuit.

-Z

 

[Divectionist]

Hi Zef

about 19 degrees will be average for that shallow test dive, and most dives from here til summer will be that and above. So we are at the coldest right now. Max is 27 surface and 25-27 at depth in summer here.

I am considering a switch to dry diving almost all year round because on a windy SI on a boat in summer, and even in the 24 degree average dive temps throughout most of the year, I do get chilled at some point, despite a good and well fitting 5mm with 2.5 hooded vest and sharkskin underneath. I don’t move much down there and often wish I was toastier or dry. So I like the idea of staying dry for a variety of reasons and may want to explore doing it all the way into summer, other than really warm days, when the 5mm alone will do. Now that we are deep in winter it’s a good time to set a cold water standard.

I’ll also be bringing some thinsulate ski underwear back from Europe soon, I assume that stuff works fine also for my subtropical purposes.

 

[Zef]

Hi Zef

about 19 degrees will be average for that shallow test dive, and most dives from here til summer will be that and above. So we are at the coldest right now. Max is 27 surface and 25-27 at depth in summer here.

I am considering a switch to dry diving almost all year round because on a windy SI on a boat in summer, and even in the 24 degree average dive temps throughout most of the year, I do get chilled at some point, despite a good and well fitting 5mm with 2.5 hooded vest and sharkskin underneath. I don’t move much down there and often wish I was toastier or dry. So I like the idea of staying dry for a variety of reasons and may want to explore doing it all the way into summer, other than really warm days, when the 5mm alone will do. Now that we are deep in winter it’s a good time to set a cold water standard.

I’ll also be bringing some thinsulate ski underwear back from Europe soon, I assume that stuff works fine also for my subtropical purposes.

Switching to a drysuit is not an all or nothing proposition, especially if you already have a wetsuit hanging in the closet or garage. I totally get your reasoning, and if it works for you great, if not you just swap out to whichever exposure suit you think best fits the weather and dive environment.

But realize, that how much insulation is needed is very personal and subjective. I use fleece of different weights depending on what the water temps are with an Aqualung Thermal Fusion undersuit for those really cold dives.

Also realize that it is the air in a drysuit, or rather the air that lofts your undergarment, that provides the insulating warmth. The form fit of the Sharkskin does not really provide for this and is only a barrier between you and the suit. In waters above 20c I can see that working ok, but at 20c and below you may want to get some thin fleece with a loose knit to trap some air and provide some insulation or use the thinsulate ski underwear you plan to buy....but like I stated, it is all very personal....I know a guy that dives a 7mm wetsuit in waters down to 2c-3c and he is comfortable, where as I am looking at switching to dry when the water temp falls to around 15c and the air temp between 10c and 15c. Your body and tolerance may find the Sharkskin perfect or you might not. Just note it in your log book and make a change for your next dive.

One other thing to be aware of is that you may find the amount of weight you need wear will change with changes in what you layer under your membrane suit. Have some extra lead on-hand to stuff into a pocket or clip to a d-ring until you get this sorted out.

-Z

 

[Divectionist]

Switching to a drysuit is not an all or nothing proposition, especially if you already have a wetsuit hanging in the closet or garage. I totally get your reasoning, and if it works for you great, if not you just swap out to whichever exposure suit you think best fits the weather and dive environment.

Yes I'll still use the 5mm on warm summer days, but rather than layering it up with the sharkskin and hooded vest for most of the year, and still being uncomfortable at times, I will probably wear it 9-10 months out of the year.

The Sharkskin is definitely warmer on its own than my thinsulate ski underwear, how well it lofts remains to be seen.

Sharkskin actually makes a full drysuit undergarment, which I was just told is the exact same thickness/material as my long sleeve, and product descriptions market it for 'colder water' under a drysuit - very curious statement given that the poll here and your estimations ranges towards being too chilly for my moderate temperature example.

I think the best thing to do will be to just go out and try it, sharkskin long sleeve and some sweat pants, then either buy sharkskin type pants if the top works out, or go to something more serious and try the sharkskin again when it gets warmer.

The Nova is on its way around the world now, should be here in a week!

 

[Marie13]

@Divectionist

No cotton under a drysuit! If your sweatpants are cotton fleece, find something else.

 

[happy-diver]

So I like the idea of staying dry for a variety of reasons and may want to explore doing it all the way into summer

Does DAN cover helicopter evacuation for heat exhaustion

Buy a jacket

 

[chris kippax]

I am a sunshine coast local so temp is same same
I wear a drysuit in May June July August September. I wear a 200gm undersuit and am comfy at 19 degrees with a run time up to 180 mins. I will be a touch chilly by the end and definitely keen to get out.
I wear a Probe I Dry 7mm for the rest of the year with similar run times. With run times around 60 minutes I would just wear a 5mm for the warmer months.
Gearing up in summer will kill you, I have gotten cooked in winter gearing up in the sun and have to often jump in quickly before donning my kit. Hopefully you got a P valve.

 

[scubadiver888]

When I bought my first drysuit I had the chillproof top and bottoms. I dive lakes with thermoclines. So at depth the water temperatures would be anything from 20C down to 5C. The sharkskin worked great for anything between 20C and 15C. I could tolerate colder for something around 45 to 60 minutes.

I essentially tried out the drysuit with the sharkskin because I didn't know how much thermal protection I would need. Once I had an idea of how well the sharkskin worked, I went out and bought some 4th Element underwear. I have worn my 4th Element in 10C to 5C water and was chilly. So I'm looking to get someone a little warmer. The end result will be three sets of underwear for different water temperatures.

P.S. I did have a leak in my drysuit last year. I found a good set of drysuit underwear, like 4th Element, was comfortable even when I was wet inside the drysuit; I didn't actually noticed right away I had a leak. But if I was wearing my sharkskin, I could tell I was wet.

 

[Divectionist]

Does DAN cover helicopter evacuation for heat exhaustion

Buy a jacket

I know from your profile picture alone what kind of diver you are - met plenty that never stop pointing out how warm they are with just their skin on - but you'd never catch me diving in boardies, not even in Cairns during summer. I am on the other end of the spectrum.

I've had days in Feb going out to 9 mile on the Goldie, chilly day, some unfortunate icy thermoclines down to 18 degrees below 20 odd metres, wind picking up during the SI - this is drysuit territory for me in summer going forward. I was cold all throughout, including the long bouncy ride back.

Then I had other days in June, glorious day, 23C average water. Totally fine in my 5mm with hooded vest.

Summer and winter, on the water around here, is not such a clear cut thing in my experience. Neither above nor below.

Gearing up in summer will kill you, I have gotten cooked in winter gearing up in the sun and have to often jump in quickly before donning my kit. Hopefully you got a P valve.

Yeah I'll have to manage that, but on hot days in summer it would still be the wetsuit. It's those colder days, long dives, cold current dives that I will still consider the drysuit for.

I've fitted a convenience zipper, not a P valve, I always need to go after not during.

The sharkskin worked great for anything between 20C and 15C. I could tolerate colder for something around 45 to 60 minutes.

This is extremely relevant for me, thank you.

I've just picked up some cheap heattech ultra thermal underwear from Uniqlo, which my always-cold girlfriend swears by, for a couple of cold destination non-diving trips and will give these a try. Wicks sweat, made of much of the same stuff as purpose scuba undergarments, should be suitable.

Top: Sharkskin + heattech ultra long sleeve shirt over the top
Bottom: Heattech extra warm + Heattech ultra warm long johns layered on top of each other

That gives me a starting point, with the ability to peel one layer off top or bottom, depending on how things go. I could imagine that just one of the heattech layers would suffice when it gets a few degrees warmer.