A compression liner is better for most men. It's a stretchy, smooth inner short that holds everything in place, stays flat against your skin, and doesn't trap sand. A mesh liner is loose netting. It's low-cost and airy, but it shifts, scratches when wet, and is the most common cause of swim-trunk chafing.
Updated October 2026 · Tucann · About 7 min read
What a swim trunk liner is for
Every pair of swim trunks needs something underneath the shell. Wet fabric clings, and loose fabric floats. A liner does three things:
- Support. It keeps everything in place when you run, dive or swim laps.
- Coverage. Stop worrying about what wet, light-colored fabric shows.
- Comfort. It puts a layer between your skin and the outer shell's seams.
There are two main ways to build one: mesh netting or a compression short. They behave very differently once you're in the water.
What is a mesh liner?
A mesh liner is the netting sewn inside traditional swim trunks. It's a loose, brief-style layer of open-weave polyester or nylon, attached at the waistband.
Why brands use it: it's low-cost, light, lets water drain fast, and it's how swim trunks have been made for decades. That's why the "why do swim trunks have netting" question gets asked so often.
Where it falls short:
- It moves. Mesh isn't fitted, so it bunches and rides up when you walk or swim.
- It's rough when wet. Open netting rubs against the inner thigh and groin. That's where most swim-trunk chafing starts.
- It traps sand. Grains get stuck in the weave and sit against your skin all day.
- It wears out. Netting snags and tears, and a lot of guys end up cutting it out. That's a common Reddit fix, and it leaves you with no support at all.
What is a compression liner?
A compression liner is a built-in short, like a light boxer brief, made from stretch swim fabric and sewn into the trunk. It fits close to the body, so it moves with you instead of against you.
Tucann's version is the Aqua-Liner. It's made from the same four-way stretch swim fabric as the outer shell, not mesh. It comes in every Tucann swim trunk: 3", 5" and 7", across every collection. Our founder, Andrew Coleman, designed it in 2017 because he was tired of mesh. That's why we call ourselves pioneers of the compression lined swim short.
What you get:
- Support that stays put. Light compression holds everything in place through laps, dives and beach sprints.
- A smooth surface against your skin. No netting, so no scratchy edges when wet. It's designed to keep chafing to a minimum.
- No sand pockets. Smooth fabric doesn't trap grit like netting does.
- No underwear needed. The liner is the underwear.
Compression liner vs mesh liner: side by side
| Compression liner (Aqua-Liner) | Mesh liner | |
|---|---|---|
| Fit | Close-fitting short, moves with you | Loose brief, shifts and bunches |
| Support | Light compression, holds position | Minimal |
| Chafing risk | Low: smooth fabric that stays in place | Higher: netting rubs when wet |
| Sand | Smooth surface, doesn't trap grit | Weave traps sand |
| Coverage | Full, short-style coverage | Basic |
| Drying | Quick-dry swim fabric | Fast-draining open weave |
| Feel out of the water | Like a boxer brief | Can feel damp and scratchy |
| Durability | Same fabric as the shell | Prone to snags and tears |
| Underwear needed? | No | No, but many guys add it (don't) |
| Best for | Active swimming, travel, all-day wear | Short dips, entry-level trunks |
Liner by activity
Lap swimming. Push-offs and kicks are where mesh shifts most. A compression liner stays in position length after length, so you're not adjusting at the wall.
Surfing and paddle sports. Long sessions plus wax, sand and salt are the classic chafing setup. Smooth liner fabric that doesn't move is the difference between a good session and a sore walk home.
Beach sports and running on sand. Volleyball, frisbee, a sprint into the waves. Support matters most here, and that's exactly what mesh doesn't give you.
Travel and resort days. Pool, lunch, bar, pool again. A liner that feels like a boxer brief means one pair takes you through the whole day, with zip pockets for your phone and card.
Kids and casual dips. For a quick paddle, liner type matters less. But if your kids are in the water all day, comfort counts for them too. See our father and son matching swim trunks.
Common myths about compression liners
"Compression means tight." Not here. Swim compression liners are light. They hold you in place; they don't squeeze like athletic compression shorts.
"They'll be hot." The liner is thin swim fabric, so it feels like part of the trunk, not an extra layer.
"Mesh dries faster, so it's better." Mesh drains fast, but a liner that dries quickly and doesn't rub is the better deal over a full day.
Which liner should you choose?
Choose a compression liner if:
- You swim laps, surf, paddle or play beach sports.
- You've had chafing from swim trunks before.
- You go straight from the beach to lunch or the bar and want to stay comfortable.
- You want one pair that handles everything on a trip.
A mesh liner is fine if:
- You only take short dips and spend most of the day dry.
- You're buying the lowest-cost trunks for a one-off.
Skip liners entirely? Unlined trunks exist, but you'll then need swim-specific underwear underneath. Cotton underwear is a bad idea in water. It soaks up water, stays wet and rubs. More on that in why wearing underwear when swimming is bad for you.
Do compression liners cause chafing or overheating?
Chafing happens when skin rubs against fabric, and moisture makes it worse. A compression liner reduces both causes. It stays in place, so there's less rubbing, and it's smooth rather than abrasive. Fit matters. A liner that's too tight digs in, and one that's too loose moves around. That's why picking the right size matters (see below).
On heat: Tucann's liner is light swim fabric, not thick athletic compression gear. Most guys forget it's there.
How to get the fit right
A compression liner only works if it fits. Order your usual waist size:
| Size | Waist (in) | Waist (cm) |
|---|---|---|
| S / 30 | 29–31 | 74–79 |
| M / 32 | 31–33 | 79–84 |
| L / 34 | 33–35 | 84–89 |
| XL / 36 | 35–37 | 89–94 |
| XXL / 38 | 37–39 | 94–99 |
Between sizes? Size up for a relaxed fit, or down for a closer, performance fit. The drawstring front and elastic back let you fine-tune it. Full details are in our size guide.
Inseam matters too. The liner sits inside whatever length you choose:
- 3": well above the knee, our shortest cut. Shop 3"
- 5": mid-thigh, our most popular length. Shop 5"
- 7": just above the knee, more coverage. Shop 7"
Not sure? Read 5 inch vs 7 inch swim trunks.
Caring for a lined swim trunk
Rinse your trunks in fresh water after every swim. That gets chlorine, salt and sand out of the liner and the shell. Dry them flat in the shade. For full washing instructions, see our care guide.
The bottom line
Mesh was the default because it was low-cost, not because it was good. A compression liner gives you support, coverage and comfort in one layer, without netting rubbing you raw by the afternoon. That's the whole idea behind the Aqua-Liner.
Over 15,000 5 star reviews · Over 500,000 global customers. Shop compression-lined swim trunks or learn how the Aqua-Liner works.
FAQ
What is a compression liner in swim trunks?
A compression liner is a built-in, close-fitting inner short made from stretch fabric, sewn into the swim trunk instead of mesh netting. It holds everything in place, gives you full coverage, and means you don't need underwear.
Why do swim trunks have netting?
Netting is the traditional, low-cost way to give swim trunks support and coverage. It drains water fast, but it's loose, scratchy when wet and traps sand. That's why many brands, including Tucann, have switched to compression liners.
Are compression lined swim trunks good?
Yes, for most men. They stay in place, cut friction, don't trap sand and replace underwear. They're especially good for active swimming, travel and long beach days.
Is it OK to cut the mesh out of swim trunks?
You can, but you lose all support and coverage, and you'd then need swim underwear underneath. A better fix is a pair with a compression liner built in.
Do you wear underwear with compression lined swim trunks?
No. The compression liner does the job of underwear. Wearing regular underwear underneath adds a wet layer that holds water and increases rubbing.
Do compression liners dry slowly?
Not if they're made from swim fabric. The Aqua-Liner is made from the same quick-dry, four-way stretch fabric as the outer shell.
