What Are Kayak Scupper Plugs Used For? Do You Need Them?

Ever wondered why your sit-on-top kayak has holes in it? These are scupper holes, and although they allow your bum to get wet, they also let water out of the cockpit, so there’s no need for bailing.

Bearing that in mind, you probably want to know what scupper plugs are and should you use them. If plugging your scupper holes allows water to fill your cockpit, what’s the point of scupper plugs?

This post will tackle the scupper plug conundrum; what they do, when and how you should use them, where you can buy them, and more.

What Are Scupper Plugs?

Scupper plugs are small rubber or plastic stoppers that you can use to block drain holes on sit-on-top kayaks. They come in various shapes and sizes. Most are either round or shaped like a bottle’s cork, but you could also mistake some types for regular sink plugs.

Some plugs screw into the deck and only fit specific kayak models. However, most universal scupper plugs push into the holes. A short cord or rope pokes out at the top, making it easy to remove them when you need to.

What Do Scupper Plugs Do? 

If you own a sit-on-top kayak, you’ve probably noticed that it has several holes in the deck. These are called scupper holes, and they allow water to drain out of your kayak (self-bailing). Unfortunately, a common problem with scupper holes is that they allow water to enter your kayak from underneath. Scupper plugs prevent this from happening because they block the holes.

If you’re new to kayaking, it’s worth mentioning that sit-in kayaks don’t have scupper holes in the deck. Therefore, you won’t need scupper plugs to paddle a sit-in kayak. This is because the cockpit is mostly enclosed, and you can use a waterproof spray deck to keep out excess water. 

Do You Need Scupper Plugs?

If Scupper plugs allow for self-bailing, you might be wondering what’s the purpose of blocking them with plugs. Naturally, scupper plugs have their advantages and disadvantages. So let’s start by discussing why you might want to use scupper plugs.

When paddling a sit-on-top kayak in choppy water, waves, or against the current, it’s common for water to splash onto the deck. Most splashes will come over the kayak’s sides, but some water will come through the scupper holes.

This shouldn’t be a problem if you’re kayaking in warm weather. But, when you’re out in cold conditions, it’s essential to keep your cockpit as dry as possible, even if you’re wearing a wet or dry suit. Scupper plugs can help reduce the amount of water in your kayak.

Additionally, scupper plugs can be helpful when you’re carrying camping gear in your sit-on-top kayak or other equipment you want to keep dry.

The flip side is that any water that comes over the sides will stay in the kayak, creating a pool of water in the cockpit. Perhaps paddling with a soggy bottom doesn’t bother you. Still, too much excess water can unbalance the kayak and cause a capsize. For this reason, beginner paddlers should leave their scupper holes open.

How Do You Use Scupper Plugs?

There’s nothing technical in using scupper plugs, so there’s no need for a step-by-step tutorial. If you’re familiar with a sink plug, you already know how to insert and remove a scupper plug. However, we have some tips for getting the right fit and when to use scupper plugs.

How to Test the Fit

One thing you should learn is how to test the fit of a scupper plug. It will leak, fall out, or get stuck in the hull if you buy the wrong size.

The best thing to do is measure the diameter of your scupper holes and buy plugs that match the size. If you need to force the plugs in, you probably need a smaller size. Remember that you’ll want to get them out again.

To test the fit, insert the plugs, fill your kayak with about an inch deep of water, and check if any water leaks from the hull. You’ll need to do this on land, preferably over a hard and dry surface, so it’s easy to see any drips.

If there’s no leakage, you’ve got the right size, but if you notice some drips, you’ll need a wider plug. 

Should Scupper Plugs Be In or Out?

Bearing in mind the advantages and disadvantages of scupper plugs, what’s the best way to use them? There are times when you should leave them out and times when you might benefit from blocking your scupper holes. Carrying a set of plugs in your kayaking kit allows you to adapt to changing weather conditions and currents.

Generally, you should leave the plugs out when paddling on flat water and while you’re learning how to paddle a kayak. A little water on the deck is normal and nothing to worry about.

However, if your kayak takes on too much water from underneath, you might want to plug the holes. Likewise, when the water and air temperature are low, we recommend using scupper plugs.

You can choose to plug all the holes in your kayak or leave some open, depending on the amount of water entering your boat. Often the best compromise is to plug the holes closest to your seat and feet but leave the others open. This will help keep your body dry but still allows self-bailing.

The other exception is when you’re carrying a heavy load in your kayak. For example, you’re bringing fishing equipment and camping gear or paddling a tandem kayak with two adult paddlers. The extra weight will make your kayak sit lower in the water and cause more water to enter.

How to Deal With Excess Water

We recommend bringing a sponge when paddling a sit-on-top kayak with scupper plugs.

A sponge is a straightforward option; it’s lightweight, absorbent, cheap, and you probably already have one in your garage. Keep it within reach when you’re sitting in your kayak and use it to soak up any excess water. Then, you can squeeze the sponge out over the side of your kayak and let it dry out on the deck.

Alternatively, you could remove the plugs when the water starts to bother you or leave one or two holes open to allow drainage.

Remove Scupper Plugs Before Storing Your Kayak

Another vital thing to know about scupper plugs is that you should always remove them before storing your kayak. Rotomolded plastic is sensitive to temperatures and can swell in hot weather. If you forget to take the plugs out, they can get stuck in the scupper holes and (worst case scenario) damage the hull.

In any case, rinsing off salt water between uses can help to extend the plug’s life. You’ll also be able to check their condition before hitting the water.

How Do You Make Scupper Plugs?

For anyone looking for a fun DIY project, why not try making your own scupper plugs? Scupper plugs are easy to make – you’ll only need a spare hour or two depending on how many you need for your kayak – and you don’t need any special tools.

What You’ll Need

• A length of cord
• Foam or rubber balls or stoppers (large enough to plug your kayak’s scupper holes)
• Plastic washers
• A long nail (approx. 5mm wide)
• Pliers (or heat-resistant gloves)
• A metal hanger or wire (to pull the cord through the balls)
• Lighter, candle, or stove (to heat the nail)

How to Make Scupper Plugs

1. Hold the nail with pliers, heat it over a flame, and melt a hole in each ball.
2. Bend the hanger so you have a small loop on the end – it will look like a giant needle. 
3. Push the hanger through the ball and add a washer. 
4. Thread your cord through the loop so that you have about 15-20 cm on either side of the loop. Cut the cord and burn both ends to prevent fraying.
5. Pull the cord through the washer and ball using the hanger and knot the open ends together.
6. Push the ball down so that the washer sits on top of the knot. If the ball moves easily, tie an extra knot on top of the ball.
7. Your DIY scupper plug is ready to use!

Don’t worry if DIY isn’t one of your strengths because scupper plugs are cheap and easy to find. You’ll be able to buy scupper plugs from most kayak retailers and watersports shops. Alternatively, you could purchase scupper plugs online.