4/3 vs 5/4: which winter wetsuit do you need for UK surfing?

November is when most people make this decision. The water has stayed mild into the autumn, the 3/2mm is starting to feel thin, and the question is whether to buy a 4/3mm now or go straight to a 5/4mm for the winter.

Price isn't what decides it. In our shop the Vissla 7 Seas 5-4 full chest zip is £349.95, and the 7 Seas 4-3 full chest zip is £329.95. That's a £20 difference for the same range. What decides it is which months you want to be warm in.

This guide compares the two using long-term average sea temperatures for Swansea and the ratings the brands give their own suits.

In short, if it's your only winter suit and you surf from January to April, buy a 5/4. A 4/3 is the better choice if you already have a 5/4, if you mostly surf in autumn and late spring, or if you run warm and keep your sessions short.

4/3 vs 5/4 at a glance

Which months each suit covers

Long-term averages for Swansea from seatemperature.org put the sea at 13.6°C in November and 11.2°C in December. It then drops to 8.7°C in January, 8.4°C in February and 8.3°C in March, before climbing to 9.6°C in April, 11.4°C in May and 13.7°C in June.

Compare those figures with the ratings and the answer is fairly clear.

A 4/3 rated for 11 to 14°C matches late October to early December, and late May to June: roughly four months, give or take a warm or cold spell.

A 5/4 rated for 8 to 12°C matches December to May: six months, and the six coldest.

The two overlap in December and May, which is why people disagree about this. In early December or late May you could argue for either. But from January to April, the average water off South Wales is below the bottom of a 4/3's rating every month. That's when a 4/3 stops being a compromise and becomes a cold suit.

There's a month-by-month table for the whole year in our UK wetsuit thickness guide.

Choose a 4/3 if you:

• already have a 5/4 and want something lighter for late October to early December, and late May to June

• mostly surf in autumn and spring and take a break in the depths of winter

• run warm and prefer short, active sessions

• go abroad on winter surf trips, where the water is warmer than at home

• swim or dip rather than surf, and keep moving while you're in

A 4/3 also makes a good first suit for someone who started surfing this summer and wants to see the autumn out before deciding whether to carry on through the winter.

Choose a 5/4 if you:

• are buying one winter suit and plan to surf from January to April

• feel the cold, or are usually first out of the water

• surf long sessions, or spend long spells waiting for sets

• surf exposed breaks, especially on the north and west coasts

• are buying for a child who wants to keep surfing through the winter, as children lose heat faster than adults

If you surf in North Wales, the north-east of England or Scotland, where the water drops further, go for a 5/4 at least, and consider a 6mm wetsuit or a hooded wetsuit for the coldest months.

Will a 5/4 be too stiff to paddle in?

This is the question we're asked most, and it's less of an issue than it used to be.

Older 5mm suits were stiff enough to leave your shoulders aching after a session. Today's limestone-based neoprenes are much stretchier, and many winter suits use thinner neoprene where you need to move. A 5/4/3 such as the Vissla 7 Seas 5-4-3 full hooded chest zip has 3mm arms, so paddling feels close to a 4/3 while your body stays warm.

You'll still notice the difference for the first week or two of winter while your shoulders get used to it. But a slightly stiffer suit that keeps you warm will get you more waves than a flexible one that leaves you cold, because cold muscles don't paddle well either.

What about a hooded 4/3?

A hooded 4/3, such as the Vissla 7 Seas 4-3 full hooded chest zip or the Vissla High Seas II 4-3 full hooded chest zip, is a genuine in-between option. The hood stops the wind taking heat from your head and neck and cuts down flushing at the collar, which makes a real difference on a windy November morning.

What a hood doesn't do is make the body of the suit any thicker. Vissla still rates both of those suits for 11 to 14°C. A hooded 4/3 is a very good late-autumn and spring suit, and a good winter suit for people who run warm, but it isn't a straight swap for a 5/4 in March.

Build quality can matter as much as thickness

Two 5/4s can feel very different. Premium suits use lighter, stretchier neoprene, better thermal linings and more thorough seam sealing, so a well-made suit can feel warmer than a thicker basic one.

One customer, Jonathan Boulding, made the same point in his review of the Vissla High Seas II 3/2 on our site: "It's very well made and incredibly warm for a 3/2... I now wish I'd spent the extra going for high seas on my 5/4 rather than the seven seas."

If you're torn, a better-built 4/3 can serve you better than a basic 5/4, and the reverse. Vissla's 7 Seas, New Seas and High Seas ranges all come in both thicknesses. See the full Vissla 7 Seas range.

Boots, gloves and a hood stretch the season a little

Accessories can extend either suit's season by a few weeks at each end. A pair of 5mm boots and 3mm gloves will make a 4/3 more comfortable in early December, and a separate hood, such as the Vissla 7 Seas 3mm wetsuit hood, takes the edge off a windy session.

They keep your hands, feet and head warm. They don't warm your body. If your chest and back are cold, the answer is a thicker suit, not thicker gloves. See our wetsuit boots, gloves and hoods.

The two-suit answer

If you surf all year, the combination that works for most UK surfers is a 3/2mm for summer and a 5/4mm for winter. When you can, add a 4/3 as a third suit for late October to early December, and late May to June.

If you're adding that third suit this autumn, the Vissla 7 Seas Comp 4-3 Chest Zip Full Suit is reduced from £279.95 to £189.95 at the time of writing. Vissla rates it for 12 to 18°C, so it's an autumn and spring suit rather than a winter one, and at that price it's a sensible way to fill the gap between a 3/2 and a 5/4.

Frequently asked questions

Is a 4/3 warm enough for a UK winter?

From late October to early December, and from late May to June, it is for most people. From January to April the water in South Wales averages 8 to 10°C, which is below a typical 4/3's rating of 11 to 14°C, so most surfers find a 4/3 cold in those months, even with boots and gloves.

Can I wear a 5/4 in summer?

You can, but you'll probably overheat once the water is above about 15°C, which in South Wales is roughly July to mid-October. A 5/4 is fine for an early-morning session in late spring, but in July and August a 3/2 is far more comfortable.

Is a 5/4 much harder to paddle in than a 4/3?

You'll notice it, mainly in your shoulders for the first week or two. Modern stretch neoprene has made the difference much smaller, and 5/4/3 suits with 3mm arms paddle close to a 4/3.

Which is warmer, a hooded 4/3 or a 5/4 without a hood?

From January to March, the 5/4 keeps your body warmer, which matters most. A hood makes a big difference in wind, so the warmest option in the depths of winter is a 5/4 with a separate hood, or a hooded 5/4.

Should a beginner buy a 4/3 or a 5/4?

It depends when you'll be surfing. If you're learning in spring or autumn, a 4/3 is a comfortable, flexible first suit. If you want to keep going through the winter, a 5/4 is the safer choice, because being cold is the quickest way to put anyone off surfing.

When does 4/3 season start and end in Wales?

Usually from late October until early December, and again from late May to the end of June. It moves by a couple of weeks either way depending on the year, so check the current sea temperature before you switch.

So which should you buy?

If it's your only winter suit, buy the 5/4. The price difference is small, the loss of flexibility is less than most people expect, and it's the suit that keeps you in the water from January to April. Buy a 4/3 when your winter is already covered and you want something lighter for the autumn and spring.

Not sure on thickness or size? 

Give us a call on 01792 387376 and tell us where and how often you surf. We'll recommend the right thickness and help you get the size right. Shop 5mm wetsuits