Purpose Of Scupper Plugs

Scupper holes, found in sit-on-top kayaks, are designed as a safety feature to drain water out of the kayak, from top to bottom, which keeps you from sitting in a puddle or even worse, making your kayak a bathtub full of water prone to capsizing. The intent of scupper plugs, designed to fit in these holes, is to keep water from coming in, which can happen in choppy water or when there is significant enough weight in the kayak to push the hull deep enough in the water to force water into the cockpit.

Remember: A Little Water Is Normal

Customers always ask me about water coming in through their scupper plugs. Don’t be alarmed, the incoming water doesn’t mean your boat is going to sink. Regardless of your kayak’s capacity and scupper plug usage, it’s perfectly normal for water to enter the boat one way or another. However, excessive water – whether it’s from spray, paddle splash, waves, or entering and exiting your kayak – consistently in your boat can become bothersome.

Bothered By Excessive Water? Carry A Sponge Or Bilge Pump

If you prefer not to remove your scupper plugs to drain water in your kayak, simply use a sponge or bilge pump. It’s never a bad idea to carry one or both of those products with you for safety and convenience. The truth is, water will always find its way into your boat. It’s just a matter of personal choice. Most people don’t like to sit in a pool of water while others don’t mind getting a little wet. If you do have some water entering your boat but want the convenience of it draining back out, consider plugging your scuppers closest to your seat and leave the ones by your feet open. Another option is to find a “drier” kayak or one that is better suited for your weight.

Most people don’t like to sit in a pool of water while others don’t mind getting a little wet.


  1. Just a warning about the ACK scupper valves. If you don’t have the brand and model listed on their cross-reference chart, you are taking a big risk in them being worthless for your kayak. Them (ACK) implying they fit everything is totally misleading.

    1. Nope, they’re for preventing water from coming up through the bottom of the kayak from choppy water (or to avoid frigid water) when you want a drier ride. Your stability won’t be impacted from scupper plugs.


    1. I would say that it will depend upon how much weight is in the kayak. If there are some large waves a considerable amount of water can come into the kayak. Scupper plugs will limit this but if water comes in over the top of the kayak, it does not have a way to drain unless you use this Scupper Valve.

  3. I have a sit on top, know nothing about them. Do you need to fill kayak with water so it sits in the water lower? I had a hell of a time trying to stay on her and finally gave up after 10 minutes. HELP ME. I want to use it but I keep falling off. It just don’t seem right.

    1. Hey George, kayaking can be challenging at first, we understand. I assure you, you will be a pro in no time! No need to fill the kayak with water, a persons body weight alone will be all the kayak needs to sit in its proper place in the water.

  4. All scupper holes are not the same size, as I found out after purchasing some at Bass Pro. The ones they sold didnt even fit the kayaks they sell

    1. Neil, I found the same problem with Bass Pro Shops and the fact that they don’t sell the scupper plug that fits my FS12T. Did you find a replacement yet? Dicks sells a universal plug that works.

    2. Hi Neil, thanks for your comment. You are absolutely right. I found this out from personal experience when I was trying to find a scupper plug that fit my Diablo Chupacabra. I tested different sizes at an ACK store until I found one that worked well. -Sam

  5. Just a thought: Have you ever considered that when flipping over with your Yak that the vacuum created with those plugs installed is much bigger, making it considerably more difficult to turn it back to it’s normal position…

    Those scupper holes do also have that function.

  6. The Necky Vectors come with this type of a scupper plug….one way valvle only letting water out. You may be able to just buy a replacement set of them and use them in any kayak with scupper holes…assuming all scupper holes are the same size.

  7. jbwilli, I would live to see a drawing or pictue on how you made them. I would be willing to buy a few sets. Any chnace oin getting some pics or drawings?

  8. We got a double sit-on- both of us are same weight (approx 13st) My partner was sitting in water in stern- I had no water. All plugs were in, some come out easy some feel stuck- we didnt try removing them whilst paddling- I had a bottle so tried to empty but kept coming in back….any advice?

    1. They already use this idea on buses in countries where it is hot inside the buses and they pressure wash them , the water on the top deck of the bus rises and the ball floats in the pipe to let the water out through a pipe that runs through the side of the bus . Water height goes down so does the ball making a air tight seal again until the next time . Basically there is already a patent on this , don’t waste your time and money with the patent office.

  9. I made ONE WAY scupper “valves” out of pvc and round fish floats for my kayak! They work great! Basically it is a float trapped inside a small 2 inch long pvc pipe. The pipe has o-rings mounted in grooves on outside, that are sized to fit the scupper holes very snuggly. Anytime water tries to come up through the scupperholes, the float inside the pipe rises and seals off pipe via an internal “seat” design inside. If watercomes into the kayak interior from any other source, splash, waves, rain, etc; everytime the float goes back down in the pipe (and it is down over 90% of the time) water drains freely out through the pipe! It is a ONE WAY water drain valve! I have the best of both worlds! That little float bobs up and down all day long, blocking water when it tries to come up through the pipe and letting water out every time it goes back down! I swear I can hear a vacuum sucking the water out everytime that float goes down if there is water covering it. It acts like wave powered bilge pump!

  10. I have a sit-on-top kayak and the last time I was fishing in the bay, two very small fish entered my boat through the unplugged scupper holes. Needless to say, they were the only fish I “caught” that day!! I prefer not to use all the plugs, just the ones closest to my seat.
    Happy Kayaking!!