Scupper holes are a feature of sit-on-top kayaks that allow water to drain out of the hull automatically. But they work both ways, and water can also come up through them from below, which surprises many first-time paddlers.
Some water coming through scupper holes is completely normal. However, there are situations where plugging them makes sense. In this article, we’ll explore how scupper holes work and when you should plug them.
How Scupper Holes Work
When you’re out on the water, water finds its way into a kayak through multiple routes including splashing, rain, dripping off the paddle, and through the scupper holes themselves. In a sit-on-top kayak, water pooling on the deck needs somewhere to go, and that’s exactly what scupper holes provide.
Most sit-on-top kayaks have between 4 and 8 scupper holes, strategically placed near the bow, stern, and seat area. Their placement ensures water drains efficiently from the areas where it tends to accumulate most. Because they pass straight through the hull, water can flow both ways, out when the kayak is riding high and in when it sits low in the water.
How To Stop Water Entering Through Scuppers
If you’re getting more water through the scuppers than you’d like, the solution is straightforward. Scupper plugs fit snugly into the holes and prevent water from passing through in either direction.
Keep in mind that plugging the scuppers removes the self-bailing function entirely. If water gets in from splashing or rain while the plugs are in, it will pool on the deck with nowhere to go. The practical solution is to carry your scupper plugs with you and use them selectively depending on conditions.
If you mainly want to stay drier without losing all drainage, consider plugging only the centre and rear scuppers. This reduces the water coming up beneath you while keeping the front scuppers open to drain any water that does come in.
What To Know When Buying Scupper Plugs
Size matters
Scupper holes vary in diameter between kayak models. Some manufacturers make plugs specifically for their kayaks, while others use standard sizes that work across multiple brands. Before buying, measure the diameter of your scupper holes. Universal plugs are available in small, medium, and large sizes and fit the majority of sit-on-top kayaks.
Material
Most scupper plugs are made from rubber or silicone. Silicone plugs tend to be more durable and maintain their shape better over time. Rubber plugs are cheaper but can degrade with prolonged UV and saltwater exposure.
Ease of removal
Look for plugs with a pull cord or handle. Removing a plug that’s sitting flush with the hull from inside the water is frustrating without one. A simple pull handle makes the whole process much easier.
When Should You Plug Your Scupper Holes?
When carrying a heavy load – A heavily loaded kayak sits lower in the water, which means more water comes up through the scuppers. Plugging them when you’re near your weight limit helps the kayak ride higher and keeps you drier.
When paddling in cold conditions – Cold water coming up through the scuppers is uncomfortable and can accelerate heat loss. If you’re paddling in cold weather, plugging the scuppers and wearing a wetsuit or drysuit is a sensible precaution.
When water is choppy – Rough water causes more water to surge up through the scuppers. In choppy conditions, plugging them reduces the amount coming in. If water still pools on the deck from splashing, temporarily remove the plugs to drain it, then replace them.
Final Thoughts
Scupper holes are a feature, not a flaw. A small amount of water coming up through them is normal and nothing to worry about. The situations where plugging them makes sense are when you’re carrying a heavy load, paddling in cold water, or dealing with choppy conditions where water is coming in faster than it can drain.
Keeping a set of scupper plugs in your kayak at all times is a simple precaution that costs very little and can make a real difference to your comfort on the water.