The Ins And Outs Of Sit-On-Top Kayak Scupper Plugs


Paddling / Friday, May 22nd, 2020

Disclosure: I am compensated for purchases made through some links on this site. Click for details.

I was really getting into kayaking in the late ’90s after taking a continuing education class in kayaking at the University of Memphis.

Loved it!

They taught us how to use sit-in kayaks. There was no mention of sit-on-top kayaks so when I first saw a sit-on-top kayak at an outfitter, I was unsure of the boat, especially the holes in the bottom. I had a lot of questions.

Maybe you’re the same as I was? Or maybe you’d like to learn more about how to use scupper plugs and their alternative, scupper valves?

My naive preconception of kayak quality led me to avoid sit-in-kayaks for years.

I don’t want you to make my mistake.

Both sit-on-top kayaks and sit-in kayaks are amazing boats. Depending on your adventure one type may be better than the other. Sit-in kayaks are better for whitewater adventures where sit-on-top kayaks are the preferred fishing kayak.

Let’s go over scupper holes, scupper plugs, and scupper valves… what they are and how they’re used.

The Purpose of Scupper Holes in Sit-On-Top Kayaks

Why does your kayak have holes in the bottom?

Well-spaced holes in the bottom of sit-on-top kayaks are self-bailing holes called scupper holes. Scupper holes in the kayak’s hull are designed to allow water that splashes inside or drips off the paddle to drain out instead of pooling in the floor of the kayak.

So if you’re wondering if your sit-on-top kayak should have open holes in the bottom, yes, scupper holes are a normal feature.

The self-bailing feature of scupper holes works to keep paddlers comfortable and safe by improving efficiency.

The additional weight of water in a kayak makes it heavier and more difficult to maneuver.

Without scupper holes in a sit-on-top kayak, a kayaker has to periodically empty water by flipping the kayak (often inconvenient) or by using your bilge pump and/or sponge, two kayak safety items that you should have.

Some kayakers intentionally plug their scupper holes. Scupper plugs aren’t used to keep your kayak from sinking. It will not sink if the holes are left open. Kayakers use scupper plugs to bypass the self-bailing feature.

Let’s take a look at how these plugs work and why you might consider using them too.

The Purpose of Scupper Plugs for Sit-On-Top Kayaks

Scupper holes in sit-on-top kayaks are for self-bailing but the pressure of waves against the hull can force water back up through the holes. This can cause problems in colder weather when cold water can have a great effect on you physically.

Scupper plugs to the rescue!

They help keep your sit-on-top kayak drier as long as rainy weather isn’t an issue and water isn’t continually splashing onto your kayak.

How do you use scupper plugs? Just pop them in the holes to keep the cold water out. You might want to keep one or two scupper holes open to provide the perfect balance of drainage and a dry deck or you can remove one as needed, use a few scupper valves, use a bilge pump, or a sponge to get rid of excess water.

Excess water impairs kayak performance so don’t let water buildup on you.

Do You Have to Use Scupper Plugs on a Kayak?

Do you need scupper plugs in warmer weather? Not at all. Most of us like getting a little wet when kayaking. It’s sorta the nature of the sport and it keeps you much cooler on hot days.

Can you use a kayak without scupper plugs in colder weather? Yes, you can use your kayak without scupper plugs in colder weather but be sure to wear the right clothes like one of these drysuits over at Backcountry. You don’t want hypothermia.

How to Install Scupper Plugs

How do you install scupper plugs? All you have to do is push these pliable rubber plugs in the scupper holes. Make sure you have the right size though.

Are scupper plugs universal? Yes and No. Scupper holes come in different sizes and shapes. The holes in some kayaks are all the same size and other kayaks have scupper holes that vary in size and shape.

When buying a universal plug, look for a plug with the proper fit for your scupper holes. For instance, Harmony scupper plugs are a great product that fits any kayak scupper hole between 1 and 1-3/8 inches.

Scupper Valves

How does a scupper valve work? Scupper valves are one-way plugs. They allow water that enters a sit-on-top kayak to drain out the scupper holes while also blocking water from splashing up through the holes.

So why on earth wouldn’t everyone use scupper valves?

  • Availability: Scupper valves are not available for all sit-on-top kayaks. Ocean Kayak Scupper Valves are the best I’ve found. They are a medium-size scupper valve for round shaped holes.
  • Maintenance: You have to keep debris from building up around the valve. If the valve is blocked, it won’t work properly.
  • Expense: Scupper valves are slightly more expensive than scupper plugs.
  • Inconvenience: Many scupper valves will stick up above the deck where plugs have a more flush fit. Because they stick up they are easier to damage or dislodge.

Using Scupper Plugs and Scupper Valves Together

Closing the scupper holes around your feet and legs with scupper plugs and using scupper valves near the kayak seat is an efficient use of resources. It also reduces your chances of damaging or dislodging a valve. You’re less likely to knock into a scupper valve close to or under your seat.

By strategically using scupper valves and plugs, you can save a few dollars and won’t have to worry as much about periodically draining water from the deck.

Conclusion

Should you plug scupper holes?

It’s a matter of personal choice but I’m for using them to stay dryer in colder weather.

The major downside to using scupper plugs is losing the self-draining benefit of sit-on-top kayaks. When water builds up in the floor of the kayak, there is a loss in buoyancy and maneuverability which is a matter of safety.

If you use scupper plugs, be sure to carry a sponge and or bilge pump for draining the water from your kayak. These items should be part of your kayak safety kit.

Don’t have a kayak safety kit? NRS has a kayak safety kit that will get you started. But be sure to check out our post “Canoe & Kayak Safety Equipment Checklist” for a complete list of safety equipment for your kayak.

I wanted to mention one additional thing that I touched on in the introduction. Classes.

Kayak classes are great for learning safety techniques. They’re also great for meeting new friends. I made wonderful lifelong friends through that class I look.

Stay safe and have fun out there!