Wetsuit Thickness Guide: 3/2, 4/3 & 5/4 by Water Temperature
Everything you need to know to stay warm, comfortable, and in the water longer.
Why Wetsuit Thickness Matters
A wetsuit doesn't keep you warm by keeping water out. It keeps you warm by trapping a thin layer of water against your skin, which your body heats and holds. The thickness of the neoprene determines how much insulation that layer provides. Get the thickness wrong, and you're either shivering through a session or overheating before you paddle out.
This guide breaks down how to read wetsuit thickness, how to match it to water temperature, and which Vissla wetsuits are built for each condition. Whether you're suiting up for a cold Pacific Northwest dawn patrol or a warm-water trip down south, this is where you start. Once you've dialed in your thickness, pair it with our Wetsuit Size Chart & Fit Guide to lock in the right fit.
How to Read Wetsuit Thickness Numbers
Wetsuit thickness is measured in millimeters. A single number like 2mm means the suit is uniform thickness throughout. Two numbers like 4/3mm mean the chest and core are 4mm thick, and the arms and legs are 3mm. The thicker section covers the core to maximize warmth where it matters most; thinner panels on the limbs preserve paddling range of motion.
Here's a quick breakdown of what you'll see on the tag:
- 2mm: Warm water, minimal insulation, maximum flexibility
- 3/2mm: The everyday all-rounder for most coastal surf zones
- 4/3mm: Cold-water full suit, sealed and ready for real chill
- 5/4mm or 5/4/3mm: Winter-grade. Add booties. Non-negotiable.
- 6/5mm: Extreme cold, typically paired with a hood
Water Temperature vs. Wetsuit Thickness Chart
Use this as your starting point. Wind chill, personal cold tolerance, and session length all play a role, but this chart covers the baseline with clean, non-overlapping ranges so you never have to choose between two recommendations.
| Water Temp | Recommended Thickness | Notes |
|---|---|---|
| 66°F+ (19°C+) | 2mm spring suit or top | Shorty, jacket + boardshorts |
| 59 to 65°F (15 to 18°C) | 3/2mm full suit | The everyday all-rounder |
| 52 to 58°F (11 to 14°C) | 4/3mm full suit | Start thinking boots or gloves |
| 45 to 51°F (7 to 10°C) | 5/4mm full suit | Add boots + gloves, sealed seams |
| Below 45°F (below 7°C) | 5/4/3mm or 6/5mm hooded | Boots + gloves + hood essential |
Note: Air temp and wind can make you feel colder before and after your session. Factor in both, especially on early mornings or late evenings.
The 3/2 Wetsuit: Your Everyday All-Rounder
If you're buying one wetsuit, a 3/2mm full suit is almost always the answer. It covers the 59 to 65°F window, which is the most common surf temp range along the US West Coast, East Coast, Europe's Atlantic, and most of Australia's east coast. A 3/2 gives you enough insulation for a two-hour session without the stiffness of a thicker suit. Better paddle power. Easier pop-ups.
Look for a 3/2 with GBS (glued and blind-stitched) seams if you're on the colder edge of the range, and flatlock seams if you run hot or surf mostly in summer. Vissla's 3/2 options span the full lineup, from the accessible 7 Seas to the performance-tuned High Seas.
The 4/3 Wetsuit: Cold-Water Workhorse
The 4/3mm is the cold-water standard, built for 52 to 58°F water. That covers Central and Northern California most of the year, the UK, Ireland, the Pacific Northwest in shoulder seasons, and winter on the East Coast. The extra millimeter of core insulation is the difference between a full session and cutting it short. Always look for sealed (taped) seams on a 4/3. Flatlock seams in this temperature range will flush cold water and kill your session.
A well-built 4/3 should still feel flexible in the shoulders. Stiffness is a construction problem, not a thickness problem. Modern neoprene and panel design mean you shouldn't feel locked up. Vissla's 4/3 options use high-stretch neoprene across the shoulders and back panel for exactly that reason.
Types of Wetsuits and When to Use Them
Spring Suit / Shorty
Short arms, short legs, typically 2mm. Built for warm water where you want some protection without full coverage. Great for summer sessions, tropical trips, and rash prevention.
Full Suit
Full arm and leg coverage, available in 2mm through 6mm. The workhorse. A well-fitted full suit in the right thickness handles the widest range of conditions.
Hooded Wetsuit
When water temps drop below 50°F, your head becomes a major heat-loss point. A hooded suit stops that. Most come in 5/4mm or 6/5mm and pair with boots and gloves for full cold-water coverage.
Wetsuit Top / Jacket
A wetsuit top worn with boardshorts is a solid mid-season move. Warmer than nothing, more flexible than a full suit. Vissla's wetsuit tops pair well with spring conditions when the water hasn't fully warmed but the air has.
The Vissla Wetsuit Lineup
Vissla builds wetsuits to perform, last, and hold up to the demands of regular surfing. Here's how the current lineup breaks down by condition.
7 Seas Wetsuit
The workhorse of the Vissla lineup and the entry point for most surfers. Available in 3/2mm, 4/3mm, and 5/4mm with reliable warmth, solid construction, and an approachable price point. Shop the 7 Seas.
New Seas Wetsuit
Built around Vissla and Axxe Classic's U-Zip entry system: the fastest and easiest in/out on the market with no water flushing on entry. High-stretch neoprene and a performance fit that doesn't sacrifice warmth for mobility. Shop the New Seas.
High Seas Wetsuit
Vissla's performance wetsuit, engineered with the highest-stretch neoprene and a precision fit for surfers who want every edge in the water. When performance is the priority, this is the suit. Shop the High Seas.
Natural Seas Wetsuit
Same session performance, lighter footprint. Built with Ocena® natural rubber and plant-based materials. If you want your gear to reflect the same values you bring to the water, this is the pick. Shop the Natural Seas.
Natural Seas & Ocena®: Vissla's Sustainable Neoprene
Traditional neoprene is petroleum-based. Ocena® is Vissla's natural-rubber alternative, made from FSC-certified natural rubber and blended with plant-based oils and oyster shell powder. The result: comparable warmth and stretch to petroleum neoprene, built with a dramatically smaller carbon footprint.
For a full breakdown, see our guide to sustainable wetsuit design.
Seam Construction: What It Means for Warmth
How the panels of a wetsuit are joined determines how much cold water enters during a session:
- Flatlock: Stitched seams that lie flat. Some water entry. Best for warm-water suits (2mm and under).
- Glued and Blind Stitched (GBS): Panels glued, then stitched from the outside only. The needle doesn't penetrate through. Significantly reduces water entry. Standard on most 3/2s.
- Sealed / Taped Seams: A liquid sealant or internal tape blocks water almost entirely. Standard for 4/3mm and up.
Rule of thumb: the colder the water, the more you want sealed or taped seams. A 3/2mm with taped seams runs noticeably warmer than a 3/2mm with flatlock in the same conditions.
Accessories: Boots, Gloves, and Hoods
Cold extremities end sessions faster than anything else:
- Boots: Add when water dips below 52°F. Split-toe or round-toe depending on board-feel preference. Thicker sole for colder conditions.
- Gloves: Start considering them under 50°F. Lobster-claw for dexterity, 5-finger for warmth.
- Hoods: Critical below 48°F. A significant amount of body heat is lost through the head in cold water.
Browse Vissla's wetsuit accessories, all designed to pair with the 7 Seas, New Seas, High Seas, and Natural Seas lineups.
Regional Starting Points: West Coast USA
Not sure what thickness to start with for your local break? Here's a rough guide to common West Coast surf zones:
- San Diego / Southern California: 3/2mm year-round. Spring suit works June through September.
- Central California (Santa Cruz / Morro Bay): 4/3mm most of the year. 3/2mm in summer only.
- Northern California / Oregon: 4/3mm baseline. 5/4mm in winter. Boots and gloves October through April.
- Pacific Northwest / Washington: 5/4mm or 6/5mm most of the year. Hood often necessary. Full accessory kit in winter.
Frequently Asked Questions
What thickness wetsuit do I need for California?
Southern California runs a 3/2mm year-round with a spring suit option in summer. Central California needs a 4/3mm most of the year. Northern California is 4/3mm baseline, 5/4mm with boots and gloves in winter.
Is a 4/3 wetsuit warmer than a 3/2?
Yes. A 4/3 has 4mm neoprene in the core versus 3mm on a 3/2, giving you roughly 30% more core insulation. 4/3s also typically come with sealed seams, which further reduces cold-water flushing.
Do I need sealed seams?
For 4/3mm and thicker suits, yes. Sealed or taped seams are essential. For 3/2s, GBS is the standard and works for most conditions. Flatlock is only appropriate for 2mm and warm-water suits.
What's the difference between the 7 Seas, New Seas, High Seas, and Natural Seas?
The 7 Seas is the accessible workhorse. The New Seas features Vissla's U-Zip entry system. The High Seas is the performance model with the highest-stretch neoprene. The Natural Seas uses Ocena® natural rubber for a lower environmental footprint.
How long should a wetsuit last?
With proper care, 2 to 4 years of regular surfing. Rinse with fresh water after every session, dry out of direct sunlight, and store on a wide hanger. See our Wetsuit Care guide for the full routine.
Can I wear a 3/2 in cold water if I add a hood?
Accessories help, but they don't fully compensate for under-thickness neoprene on the core. If you're consistently surfing below 58°F, step up to a 4/3 rather than layering over a 3/2.
What size wetsuit should I get?
Wetsuits should fit snug with no gaps at the lower back, chest, or crotch, but without restricting your paddle stroke. See our Wetsuit Size Chart & Fit Guide for brand-specific sizing.
Is natural rubber as warm as traditional neoprene?
Yes. Vissla's Ocena® natural rubber performs comparably to petroleum-based neoprene in both warmth and stretch, with a significantly smaller carbon footprint.
Find Your Suit
Thickness is the first variable. Fit, seam construction, entry system, and material all affect how a suit actually performs in the water. The Vissla wetsuit lineup is designed to nail all of them. Explore the full wetsuit range and use this guide to land on the right thickness for your conditions.