Open Water Swimming: Why a Rash Guard Belongs in Your Kit

Open water swimming is a different beast from the pool. You're dealing with cold water, UV exposure, wind chill, and surfaces that don't come with lane ropes or a lifeguard. The kit you bring matters more, and yet most open water swimmers spend far too long thinking about wetsuits and not enough time thinking about rash guards.

Here's why that's worth reconsidering.

What Makes Open Water Swimming Different

Swimming outdoors exposes you to conditions that a pool never throws at you. Direct sunlight reflecting off the water surface can cause significant UV exposure even on overcast days — and prolonged exposure while swimming adds up fast when you're face-up or doing backstroke. Wind chill between open water sessions, walking to the entry point, or waiting on a beach can strip body heat quickly. And natural surfaces — rocks, rough shingle, reeds, weed — can graze or irritate exposed skin in ways you simply won't encounter in a pool.

A rash guard addresses several of these at once.

UV Protection

The UPF (Ultraviolet Protection Factor) rating on a good rash guard is one of its most underrated features for open water swimmers. Most quality rash guards carry a UPF 50+ rating, which blocks over 98% of both UVA and UVB radiation. Sunscreen washes off in water — UPF fabric doesn't. For open water swimmers doing longer sessions, this protection is meaningful.

At WhatUWant2Buy, our rash guards are made from 82% polyester and 18% spandex with a four-way stretch construction and UPF 50+ protection — giving you full freedom of movement without sacrificing sun defence.

Wind Chill and Thermal Management

Rash guards aren't wetsuits — they won't keep you warm in cold water the way neoprene does. But they do provide a meaningful layer of protection against wind chill when you're out of the water. That transition period — exiting a cold lake, walking back to your kit, waiting at the shore — is where body temperature drops fastest. A rash guard gives your skin a base layer that holds a little warmth and cuts wind exposure, making recovery between swims more comfortable.

Skin Protection

Open water entry points aren't always clean concrete steps. Shingle beaches, rocky shores, and silted lake beds create friction and abrasion risks. A rash guard covering your torso and arms provides a physical barrier that reduces scraping and irritation — which is exactly the job rash guards were originally designed for in surfing, before they crossed over into mainstream swim kit.

Long Sleeve vs Short Sleeve for Open Water

For open water specifically, a long sleeve rash guard is usually the better call. The additional coverage protects more skin from UV, offers more wind protection out of the water, and provides better coverage against vegetation or rough surfaces during entry and exit. Short sleeve guards are perfectly usable, but the marginal extra warmth and coverage of a long sleeve version tends to justify the choice in most open water environments.

If you're unsure which to pick, our long sleeve vs short sleeve rash guard guide covers the key differences in detail.

Can You Wear a Rash Guard Instead of a Wetsuit?

This is the question most open water swimmers eventually ask. The honest answer: it depends on water temperature. In water below around 16°C, thermal insulation from a wetsuit is important for safety and comfort. In warmer open water — Mediterranean coastlines, warm-season lakes, tropical settings — a rash guard is a perfectly reasonable wetsuit alternative for shorter swims. It's lighter, easier to get on and off, and far less restrictive.

For many open water swimmers doing summer wild swims in the UK, a rash guard combined with a tow float and bright colours is a practical setup that doesn't involve the time and faff of neoprene.

Visibility

This one is often overlooked. A brightly patterned rash guard increases your visibility in open water — to other swimmers, to boats, and to shore-based support. At WhatUWant2Buy, our rash guards are available in vivid all-over print designs across more than 20 art styles, which means high visibility comes as a natural feature of the aesthetic rather than a compromise.

What to Look For in an Open Water Rash Guard

• UPF 50+ rating — non-negotiable for sun protection
• Four-way stretch — freedom of movement through a full swim stroke
• Flatlock seams — reduce chafing on long sessions
• Long sleeve option — for added coverage and wind protection
• Bright or high-contrast design — for open water visibility

Browse Our Rash Guards

Our full rash guard range is available for men, women, youth, and kids, in a wide range of AI-generated designs across seasonal and art style themes. All feature UPF 50+ protection and four-way stretch construction.

Browse all rash guards at WhatUWant2Buy

This article was written with the assistance of AI and reviewed and approved for publication by the editorial team at WhatUWant2Buy.