Back in the day, you maybe wore a sweatshirt and leggings under a neoprene suit or a woolly bear under a membrane suit.
If you’ve never seen a woolly bear, it was a one-piece garment that effortlessly combined minimum thermal efficiency with a marked lack of style, but at a price low enough for you to overlook the deficiencies.
Things change, however, and new materials and combinations of materials have revolutionised undersuits.
Take the Otter Polar System undersuit. This comes in a number of styles and thicknesses, including single- and double-layer suits, zippered onesies, top and trouser sets and zipped jackets. The undersuits are made to order and come in a nifty drawstring kitbag.
The one Otter sent us was the Polar System-D two-piece, consisting of high-waist leggings and a large, round-necked sweatshirt-style top. The
D signifies that the garments are made from a double thickness of material, a soft, comfortable inner fleece layer and a micro-fibre outer layer.
Otter says that pretty much any warmth escaping through the inner fleece is reflected back from the outer layer to keep you as warm and cosy as possible.

The Design
The thick, soft pants have a draw-cord to hold them up. The fleece material then runs all the way down the legs to just below mid-calf, when it switches to become a thin sock affair, with a loop that goes under your foot to hold the leggings in place when you pull your suit up over them.
The sweatshirt is thick and cosy-feeling even before you pull it on. Around the collar is a soft, knitted cuff that sits high on your neck for maximum warmth, but without interfering with your neck-seal.
Similar cuffs around the wrists keep the insulation of the suit going all the way down your arms to the edge of your
wrist-seals.

Donning
A thumb-loop on each wrist allows you to hold the undersuit arms in place as you don the top half of your drysuit. The bottom of the sweatshirt simply falls into place over the top of the bottoms, with a good overlap to keep your middle especially warm.
Pulling the two halves of the undersuit on is a breeze, and immediately it’s lovely and snugly – not words I ever expected to use to describe diving gear, but I really don’t have an option.
You know how you feel when you have a lie-in, when the bed is warm and soft and you just don’t want to get out? Yup, the Otter undersuit feels just like that.
It even blocks the wind effectively, so you stay warm in those minutes between climbing out of the car and putting on your suit.
And nothing much changes when you’re zipped into your drysuit. Even on a cold, cold morning with horizontal sleet and a biting wind you’ll be fine as soon as the suit zip closes, hands and ears excepted.
And if it’s even a moderately warm or sunny day you’ll be glad to get into the water to cool down, which is why Otter offers a thinner version of the suit for summer.

In The Water
And does it continue to do the business when you go diving?
Yes, it does. In a membrane suit in water at 2° I was OK even after half an hour spent fiddling about with cameras and not actually moving much.
In a neoprene suit in 4° water, I honestly didn’t even think about the water temperature.
In direct competition against my own well-worn Thinsulate, which is admittedly losing some of its loft as it ages, the Otter combo was hands-down winner, and a sight easier to shove into my suit.
Anything not to like? Well, if you take a look at the pictures you might feel that it isn’t the most elegant of garments, but then I make no claims to being the most elegant of wearers, so that’s all right.
Other than that, I’d perhaps like the trousers to be an inch or two longer in the body and come with a set of braces to hold them up, and perhaps a longer tail on the back of the sweatshirt would be nice, but that’s gilding the lily.

Conclusion
This Otter Polar D undersuit combination is very, very good, and worth every penny of the price. Wearing it in the water I was closer than I’ve ever been to toasty-warm, and I can’t say better than that.


SPECS
TESTER: Mike Ward
PRICES: £162, or top and trousers £81 each
SIZES: XS, S, M, L, XL, XXL
COLOURS: Black, with blue, white, red, black, pink or yellow stitching
WEIGHT: Top 800g, trousers 600g
CONTACT: drysuits.co.uk
DIVER GUIDE 10/10