Can You Wear a Rash Vest in a Swimming Pool & the Ocean? Complete Guide!


If you participate in water sports, such as surfing and/or swimming, regularly, you most likely own a rash guard (or swim shirt), or, at least, know someone who does. As such, you may be wondering if you can use a rash guard for swimming in the pool (and ocean).  

Yes! One can swim in a rash guard in the pool or ocean, though, it may not be as comfortable as other options available on the market. 

A rash guard is a shirt (or vest) that is made from polyester, nylon, elastane (lycra/spandex), or a combination thereof.  As the name suggests it is designed to protect (guard) one from a rash (chaffing).  You can find three different types of rash guards on the market: 

  1. Long-sleeved
  2. Short-sleeved (t-shirt)
  3. Sleeveless (also referred to as a rash vest)

While rash guards initially gained their popularity with surfers to help them avoid painful chafing (rash), from the constant contact of their body with the surfboard and the aquatic (ocean water) environment, they have since become popular for those simply swimming and/or lounging by the water- whether it’s the pool or ocean (beach)- and wanting a little added cover/protection.  

In fact, wearing a rash guard has additional benefits. A rash guard not only protects against chaffing/rash but also protects against ultraviolet (UV) rays.  This protection from UV rays (the sun) helps one reduce their risk of sunburn. Additionally, it reduces the amount of skin exposed to the sun and thereby how much sunscreen one must use (sunscreen can have adverse effects on water-both pools and the ocean). Not only does it protect one’s skin from the sun, but it also protects it from the water and aquatic life (i.e., plants and animals in the water/ocean). 

In addition to protecting one’s skin from the sun and aquatic life (and chaffing/rash), a rash guard can also help protect against cooler water temperatures. And, finally, rash guards have a slim, snug fit which means they will provide a nice streamline, won’t move around/bunch up, or weigh one down (as compared to a regular t-shirt or looser fitting swim garment) while swimming (i.e., it won’t get in your way while swimming).

Rash guards have been used by surfers and other water sports participants (athletes) for decades now. But, as said, the use of rash guards amongst swimmers, in particular,  is growing in popularity- whether it’s for swimming or just lounging by the water/other outdoor activities (i.e., the number of swimmers, and non-swimmers for that matter, using rash guards for swimming and/or beach/ pool/outdoor apparel is growing).  So long as one follows the manufacturer’s guidelines, they can [safely] use a rash guard for swimming in the pool or ocean.

While rash guards are typically made from materials safe for pools, always be sure to check that your pool allows for their use. Also, check the label of the shirt to assure it is okay to wear/use in chlorinated and/or salty water (and be sure to follow the care instructions).

(Source A)(Source B)(Source C)

What Is the Difference Between a Rash Guard and A Swim Shirt?

Anyone that spends a significant amount of time in the water, whether competitively or for leisure, can vouch that rash guards and swim shirts are two must-have items. But, wait- are they not the same thing? What exactly is the difference between a rashguard and a swim shirt? 

A (rash guard) swimming shirt is a different “model” (style) from the traditional rash guard. You could think of rash guards and swim shirts as cousins- they are essentially the same thing but have some technical differences. The main difference between the two is in the way they fit

A swim shirt (sometimes called a rash guard swim shirt or surf shirt) is designed to protect from UV rays (and it won’t wash off like sunscreen!). Much like a rash guard, swim shirts also have chafe-free seams. The swim shirt fits loosely as compared with the rash guard (which is designed to fit snugly). 

The loose fit may create some added drag (a potential turn-off for those that are looking to wear it when swimming competitively/for time) when swimming but is typically more comfortable when taking part in other activities such as walking the boardwalk or hiking, or, even, gardening [as well]. Swim shirts are made from nylon and spandex and, sometimes, polyester- making them much more ideal for swimming (and other outdoor activities) than a regular t-shirt. 

Rashguards, on the other hand, because they were initially designed for surfing (water sports) fit snugly- like a compression shirt for the water. Rashguards are typically made of nylon and spandex  (i.e., they’re comfortable)- this helps provide stretch while maintaining its shape (i.e., a good fit). 

While rash guards have always been a type of athletic top designed to protect surfers (and, nowadays, swimmers) from chafing, swim shirts have always been designed to protect against UV rays while being comfortable in the elements and while being active. As such, one will want to be mindful of the looser fit of the swim shirt. Due to their loose fit, you will want to assure an appropriate fit for your swim shirt- it doesn’t need to be very snug, but you don’t want it too loose either. (Because of the looser fit, some find the swim shirt more comfortable than the rash guard.)

So then, which should one go with? Ultimately it comes down to personal preference. Both rashguards and swim shirts offer skin protection from the sun’s UV rays as well as the water/aquatic life; however, only the rashguard offers a level of compression. So, ultimately it comes downs to what exactly you will be doing in the water/when wearing it and/or which is more comfortable to you (i.e., what are your needs and use for the rashguard/swim shirt?- those needs will dictate which is the best option for you). 

Rashguard= tight (snug), form-fitting

Swim shirt= loose, conforms to the body 

(Source A)(Source B)(Source C)(Source D)

Do You Wear a Rash Guard Over a Swimsuit? What Do You Wear Under a Rash Guard? 

So, you know what a rash guard is and about its close cousin, the swim shirt. But, you’re wondering “how exactly does one wear a rash guard? Does it go over one’s swimsuit?”, or, maybe, “ what do you wear under a rash guard?”. 

First, rash guards come in many different styles and are designed for all ages- everyone from toddlers to adults. The fit will also dictate how it is worn. A rash guard, while it fits more snugly than a swim shirt, can still come in a loose fit (versus the traditional snug fit). There’s also a variety of sleeve lengths (long, short, sleeveless).  So ultimately it will depend on what one is doing when wearing the rash guard (or swim shirt) and what is most comfortable (as well as appropriate). 

Females (women) will typically wear their normal swimsuit, whether it be a one-piece or two-piece- a tankini or bikini, under a rash guard (or swim shirt).   Though rash guards may offer slight compression they don’t particularly offer the support or coverage one may be looking for. Wearing a swimsuit underneath not only provides a little added modesty but is also often more comfortable (i.e., provides support).

Males (men) will typically wear their rash guard (or swim shirt) with their swim trunks or board shirts- much like a regular shirt, but this one is specifically designed for being in the water/water activities.

In other words, men (males) do not need to wear anything under their rash guard (or swim shirt) while women (females) should, preferably at least, wear a swimsuit underneath. 

(Source A)(Source B)(Source C)

Can You Swim Laps in A Rash Guard?

Rash guards were originally designed (in Australia) for surfers to help protect them from chafing/rashes from their boards/water/sand. And, nowadays, they may typically be seen used in other open water sports such as [open water] swimming, snorkeling, and triathlon. But, can one wear a rash guard to swim laps [in a pool]? Or, pondered another way, “can I swim laps [in a pool]  in a rash guard?”. 

Absolutely! One can swim laps [in a pool] in a rash guard.

While they were originally designed for surfers (open water/ocean use), they have become widely used amongst swimmers and those that participate in other water sports (such as triathlon and/or competitive swimming). 

Because a rash guard is designed to fit snugly, it does not impede movement while swimming. Some do prefer a short sleeve over a long sleeve rash guard for optimal shoulder movement. 

If one prefers a looser fit, they could opt to swim laps in a loose fit rash guard or a swim shirt- the close cousin of the rash guard that doesn’t fit quite as snugly. Just be mindful that the looser it is the more drag (i.e., water resistance) it will create. Thus, wearing a rash guard (or swim shirt) while swimming laps may not help you concerning [improving] your time(s). 

Additionally, unlike cotton clothing which can harbor bacteria (requiring more chemicals to be used in the pool water to keep it sanitary) and break down due to the chemicals in pool water, rash guards are fine for swimming pools as they are typically made from a nylon or polyester elastane (lycra/spandex) blend (both of which are more suited for a chlorinated environment). (Source A)(Source B)(Source C)

Do Rash Guards Make You Swim Slower?

Like any other swim garment, rash guards come in many different fabrics, sizes, styles, and even thicknesses (it really depends on the purpose of the rash guard).  Nowadays,  particularly, rash guards are not just used for surfing- they’re used for many other water sports/activities, including swimming.  Thus one may be wondering if a rash guard will slow them down [in the water] (i.e., will a rash guard make them swim slower?). 

Unfortunately, there isn’t much research out there answering the question of whether or not rash guards make one swim slower. However, logical reasoning would allow one to surmise that anything that does not fit like a second skin (or glove) and/or that has holes/pockets has the potential to create drag (water resistance), and, thereby, slow one down. 

So, first, let’s assure we all have the same understanding of the rash guards’ purpose as they serve a few different purposes. Then we will address the fit.  The purposes of rash guards include 

  1. Rash protection (duh!)
  2. Protection from the sun 
  3. Protection from aquatic life (animals and plants)
  4. Protection from cooler water temperatures (note: it is not a replacement for a wetsuit, nor is it suitable to keep one warm in extremely cold water) [note: swim performance, i.e.- whether or not one would swim slower (or faster), is not listed as one of its purposes]

Next up, is the fit of rash guards. Rash guards come in two different fits – snug (a.k.a. skin tight) or loose fit. Which fit to go with depends on what you are using it for.  When it comes to swimming (particularly swimming for time/competitively) one will want to consider a snug-fit rash guard (versus the loose fit) to keep drag (water resistance) to a minimum (i.e., to not slow them down). (The snug fit will be the closest fit to “fitting like a glove/second skin”.)

Depending on the exact fit (style) of one’s rash guard and other factors such as water conditions and swimming technique,  it is possible that a rash guard would slow one down. Some have reported that their times were 5-15 seconds slower on their 100 time(s) when wearing a rash guard (versus when not).  

(Source A)(Source B)

Do Rash Guards Keep You Warm in Cold Water?

A wetsuit can be cumbersome- sometimes it’s just too much. But, one still needs to keep their skin and body protected when swimming in cold water/colder temperatures. This has, at least a few, people turning to the rash guard and wondering if it will do the job to keep one [sufficiently] warm. 

A rash guard does provide a barrier between one’s skin and the water. As such, it will keep one slightly warmer than if they were to wear only a swimsuit; however, they are not designed to lock in body heat (i.e., be warming layers) and, as such, are not very good at keeping one warm (particularly in cold water)

The basic purpose of a rash guard is not to keep one warm. It is to protect one’s skin from abrasions (chaffing) (and UVA/UVB rays). Also, rash guards are thin and breathable, and, thereby, they do not insulate one well. 

Though the rash guard does not insulate well and is not intended to keep one warm in the water (especially extremely cold water), it can be a great alternative when it is too warm for a full wetsuit. 

Ultimately, if you’re needing warmth while in the water you will want to opt for a wetsuit (or drysuit). While a rash guard does provide some warmth, it is not a sufficient amount. A rash guard is better suited for warmer waters or wearing under a wetsuit/drysuit for added warmth/protection.  (Source A)(Source B)

(It is worth noting that there are some rash guards on the market that are designed with protection from the cold in mind. These rash guards are often made from a neoprene material versus a nylon/polyester blend)

Do Rash Guards Dry Quickly?

Rash guards are typically worn under a wetsuit (or drysuit) or over a swimsuit. Nowadays, rash guards are not just for surfers. Athletes across many different sports have found them beneficial and started wearing them. 

Among the questions one has regarding rash guards, they may be wondering whether or not rash guards dry quickly.  Indeed, a quick-dry time is one of the pros of a rash guard

Rash guards are typically made of a nylon or polyester blend. This means they are lightweight and breathable and dry quickly.

This leaves one cool, dry, and ready for the next activity of the day (in no time). (Source

Can You Do a Triathlon in A Rash Guard?

Whether it’s a rash guard, swim shirt, or wet suit it seems like the options could be endless for a triathlon/triathlete. As such, one may be wondering which of these they can wear to do their triathlon/as a triathlete. 

Ultimately, it is going to depend on the triathlon event rules and regulations as well as your [personal] comfort. So long as it is legal for your particular triathlon event (i.e., the water temperatures are warm enough and they are permitted) and one finds them comfortable, one could wear a rash guard- though, it may not be the best option.

Oftentimes, athletes will wear a rash guard under their wetsuit for added protection and/or warmth in colder waters. And, on occasion, when it is warmer, some will opt to wear a rash guard with their regular swimsuit to provide their skin with added protection (as well as make some of the transitions easier) versus donning a wetsuit. 

Though it may be legal to wear a rash guard in a triathlon/as a triathlete and they can provide added warmth under a wetsuit, due to their design/style (i.e., fit), it may not be the best option [for optimal performance] by itself.  Said another way, because of its fit, the rash guard has the potential to slow one down (i.e., it can create drag/water resistance). (A tri suit or tri top may be a better option.) (Source A) (Source B

How Tight Should a Rash Vest Be?

So, you’ve established what a rash guard is and when to wear it, but now you’re wondering how it should fit. … Should it be loose? Does it need to be tight?  

Yes and No (to the latter). Rash guards are meant to be form-fitting (i.e., fit snug/tight), but they shouldn’t restrict movement. After all, they are designed to protect you from the sun and chafing without hindering your performance (i.e., slowing you down). So, they can’t be flowing and moving around, but they shouldn’t be so snug/tight that one can hardly move. 

Everyone’s [specific] size will be different, obviously, but, in general, a rash guard should fit slightly tighter than a typical t-shirt [would for you]. Just be mindful that it isn’t too tight (or too loose). So, a good rule of thumb when trying them on is to assure that you have a full range of motion in your arms while wearing the [particular] rash guard. 

Remember, it should be snug/form-fitting/tight, but not uncomfortable (i.e., it shouldn’t restrict movement in any way while being snug) 

Also, because rash guards are meant to protect against chafing and as such need to fit snugly (so they stay in place), one should avoid “unisex” styles as they will not be appropriately shaped/fit and could cause chafing and/or just be uncomfortable. 

So while a rash guard should usually be tight/form-fitting (i.e., fit snugly), comfort is the most important thing. Make sure it fits right for you and the purpose you intend to use it for. Ultimately, it depends on preference (and intended purpose)- those that are swimming competitively may want to opt for the tighter fit while those swimming for leisure may prefer the looser fit.  Either way- just assure it isn’t too loose or too tight and allows for a full range of motion. (Source A)(Source B)(Source C)

Is a Rash Guard the Same as A Compression Shirt?

Though a compression shirt very closely resembles a rash guard, it is not [exactly] the same thing. Both a compression shirt and a rash guard will fit snugly (i.e., they both have a tight fit); however, their purpose is where they truly differ. 

As has been read here in this article, rash guards were designed to protect one from the sun’s UVA/UVB rays and from the elements of the water and sport (i.e., surfing, and, nowadays, swimming) that cause chafing.

Some areas of a rash guard have a bit more give due to the addition of elastane (stretchy/elastic material), while other areas are tighter to help minimize (and, optimize) range of motion (movement). A rash guard, while designed with a snug fit like a compression shirt, typically has a more relaxed (loose) fit than a compression shirt. 

The purpose of compression garments (such as a compression shirt), on the other hand, is to promote better blood flow (i.e., increase blood flow) and support muscles.  This better/increased blood flow increases the amount of oxygen being circulated and helps to regulate one’s [(core) body] temperature. To create this increased blood flow, the garment must provide compression. Thus, compression garments, such as compression shirts, fit extremely snug- in fact, they mold to the body.  

Because of the increased blood flow and oxygen being circulated, compression gear has been said to contribute to improved athletic performance during workouts/training/exercise. In other words, according to manufacturers, the design of compression gear prevents injury and reduces muscle soreness, thus, improving one’s performance. However, it should be noted that the [scientific] research and evidence supporting performance claims are mixed. 

While a rash guard and compression shirt look similar at first glance and are worn by athletes and non-athletes just the same, they are, in fact, different. A compression shirt is not just tight, but it is tailored (i.e., it molds to the body). A rash guard will fit snug and be form-fitting but will be looser than a compression shirt. 

Ultimately it will come down to you, the wearer. Go with whichever is more suitable to your needs/activity and, ultimately, comfortable- if you prefer the molded snugness and/or are looking to [potentially] improve performance, go with the compression shirt. If you prefer a slightly less snug (i.e., looser) fit and will just be swimming leisurely/lounging around the water, opt for the rash guard. (Source A)(Source B)(Source C

Melissa Frank

My passion, outside of animals, is helping people and adding value to their lives…I strive to leave the world a little better than I woke to it each day. The first part of my career, for a total of about 15 years, was spent in the public safety field as a Volunteer Firefighter/EMT-B and 9-1-1 Operator. In 2019 I obtained my personal trainer certification (ACE certified) as well as many group fitness certifications and certification as a Corrective Exercise Specialist.

Recent Posts