Rash guards are a piece of clothing that you would use for water activities. It is relatively thin and will protect your skin from the elements. But what do you wear under a rash guard when it is almost a ‘second skin?’ Can you go commando? We will look at the do’s and the don’ts to wearing a rash guard, when it is appropriate to wear one, and also how best to clean your rash guard so that it is always ready for your next water adventure!

WHAT IS A RASH VEST USED FOR?

A rash vest or rash guard acts as a barrier from the sun, sand, salt, and stinging organisms during water activities. It can also be used under a wetsuit where its prime use would be to stop the wetsuit from rubbing and causing ‘rashes’ against your skin. When worn alone in scuba diving, it will also stop the BCD straps from digging and rubbing against your skin too.

Daci Women Two Piece Rash Guard Long Sleeve Swimsuits UV UPF 50+

Quiksilver Men’s All Time Short Sleeve Rash Guard

Another reason to use a rash vest would be as an extra thermal layer to keep you slightly warmer. Check out how rash guards keep you warm here. You can get tight fitted rash guards or loose fitted rash guards and use them for the following activities:

YOU WOULD WEAR A TIGHT FITTED RASH GUARD WHEN

  • Layering it under a wetsuit. This stops the material from bunching up under a wetsuit which can cause chafing or be uncomfortable.
  • Surfing so everything is streamlined and does not flap around when getting speed!
  • Snorkeling and swimming. A tight fitted rash guard will not ride up as you swim around.

YOU WOULD WEAR A LOOSE FITTED RASH GUARD WHEN

  • Just hanging at the beach
  • When it is used only as protection from sunburn and harmful UV sun rays
  • When planning easy activities such as paddle-boarding

Naviskin Men’s Quick Dry UPF 50+ Sun Protection Long Sleeve

BALEAF Women’s Long Sleeve Half-Zip Sun Protection Rashguard

WHAT DO MEN WEAR UNDER A RASH GUARD?

The vast majority of men do not wear anything under their rash guard and can be used directly on the skin. When it comes to the leggings, it can also be worn without anything under but for hygienic reasons, it is recommended to wear swim briefs or swim boxers.

Speedo Men’s Swimsuit Square Leg Endurance+ Solid

Speedo Men’s Swimsuit Brief Endurance+

Swim trunks and board shorts, that are not tight-fitting, do not go well under those leggings as they can bunch up under the leggings and be uncomfortable. This could cause chafing, especially between the legs!

WHAT DO WOMEN WEAR UNDER A RASH GUARD?

Women can also wear their rash guard without anything underneath, however, many women will not choose to. Rash guards will not give you any chest support which is something to consider when doing any strenuous activities.

The stretched fabric of a rash guard also has a tendency to become transparent when wet. Something that you will definitely need to think about when deciding what to wear under a rash guard! That is the reason why it is usually recommended to wear a swimsuit under the rash guard. It is also nice to be able to take your rash guard off in between activities so your skin can dry off quicker.

TYR Sport Women’s Solid Diamondback Swimsuit

TYR Sport Women’s Solid Durafast Diamondback Workout Bikini

Bikini or one-piece, both are perfectly acceptable. But you should pay attention to the accessories: tie knots, metal rings, dangling decorations; these look nice, but under a tight rash guard, they can be uncomfortable and rub against the skin.

You may also wear sports bras/underwear as these are usually sturdy and quick-drying; perfect for watersports. Deciding what to wear under a rash guard will be quite similar to what women wear under wetsuits.

WHAT DO KIDS WEAR UNDER A RASH GUARD?

There are many colorful designs and patterns on rash guards for children. You can also pick up a top and short combination rash guards for kids, which is perfect for a day on the beach. Most kids will not wear anything extra under a rash guard; maybe a diaper if still needed!

Simple Joys by Carter’s Girls’ 3-Piece Rashguard Set

Body Glove Boys’ 2-Piece UPF 50+ Rash Guard and Swimsuit Trunks Set

CAN YOU TAN THROUGH A RASH GUARD?

Your skin tans as a response to injury from ultraviolet light, and the most common UV light will be from the sun. Good branded rash guards will usually be made from fabrics with an ultraviolet protection factor (UPF) of 50+. This means the fabric is made of tightly-woven fabric and higher-grade materials, which won’t allow harmful rays onto your skin, which means you won’t tan as easily!

Watch out for areas that are not covered by your rash guard; hands, face, back of the neck, legs, and feet. Make sure to cover those areas with a marine safe sunscreen at least 1 hour before hitting the water so that the sunscreen actually soaks in and protects your skin!

CAN I WEAR A RASH GUARD TO LUNCH?

Rash guards are becoming more stylish with cool designs and patterns. However, this still does not make it ‘street-wear!’ A casual lunch at a beachside cafe will see some diners still wearing their rash guards, which is mostly acceptable. A fine-dining establishment, however, will probably not be keen on you walking in with a dripping wet rash guard!

HOW OFTEN SHOULD I WASH MY RASH GUARD?

Never put a rash guard through the washing machine or wash it too frequently.

If you are still planning on using the rash guard; for example, you are still on holiday or diving on a liveaboard then the best thing to do is to rinse your rashie properly in freshwater at the end of the day, or a quick rinse in between dives.

This will remove any salt residue from the ocean water. Turn it inside out and then air it out in a well-ventilated area and hang it out to dry away from direct sunlight or heat. The sunlight can cause the material to discolor, and heat can weaken the structure of the material.

what do you wear under a rash guard snorkeling woman underwater
Photo by John Cahil Rom from Pexels

If you are not planning on using the rash guard for a few months, then you can properly wash the rash guard by using some soap or antibacterial liquid (like Dettol) and leave the rash guard to soak for an hour. Don’t wring the rash guard out as it can weaken the fabric. Just leave it to drip dry out of the sunlight. 

Pro Tip: Make sure the rash guard is completely dry before storing it away. A stinky smelly rash guard is disgusting, and can be smelt by everyone on the dive boat!

CONCLUSION

Rash guards are not only a fashion trend, but they are also really useful for those who enjoy water sports. Australian surfers understood it a long time ago and now the diving community is also starting to adopt it, due to its many benefits under and above the water.

A rash guard is great to protect your skin and allow you to enjoy snorkeling without having to worry about sunburns or scratches caused by rocks.

Rash guards are also great when you have finished your dive to protect you from the sun, or the chilly breeze caused by the boat speed.

It is your choice to decide on what do you wear under a rash guard when going on your water activities. But our suggestion would be to go with something comfortable that will work for that particular activity. You might even have several rash guards for different purposes! Either way, wearing a bathing suit or swimwear is a great idea for women as it provides support and modesty. And for men who wear rash bottoms; swim shorts or swim undies are great for hygiene purposes.