Can You Fill a Kayak with Foam ?

Kayak owners (especially those that spend time paddling in rough or choppy water) are smart to add extra buoyancy to their watercraft on top of buoyancy features built right in when these boats slide off of the assembly line.

But can you fill a kayak with foam and have it generate any real impact ?

You can fill a Kayak with foam to add buoyancy, even out weight distribution, and help your kayak track a little straighter and move a little faster through the water.

At the same time, you need to be smart about how you add foam to your vessel.

Add the wrong foam – or add too much or too little – and you’ll end up causing a whole bunch of headache you don’t want to deal with, especially while you’re out on the water.

Filling a kayak with foam strategically can improve the overall performance and “water worthiness” of your kayak at the same time.

In fact, you’ve probably noticed that almost all brand-new kayaks roll off of the assembly line and are sold in stores filled with bits and pieces of Styrofoam throughout the inside.

Some people think that the Styrofoam is some sort of packaging material and jettison it just as quickly as humanly possible. Others recognize Styrofoam in a kayak for what it is – foam that helps the boat float above the waterline – and leave it intact.

You’ll be able to add extra foam to your kayak for sure!

Why Would You Add Foam to a Kayak in the First Place?

It stands to reason, then, that if the manufacturer of kayaks are stuffing foam into your boat than you could add a little more and increase the buoyancy and even make your kayak easier to retrieve any event of a capsize situation.

Increased Buoyancy

There’s a bit of a myth and misconception out there about foam making your kayak ride a little higher in the water, and the more foam you add the more the higher your kayak is going to sit – making it easier to move through the water, helping it track straighter, and generally making it a lot faster.

In real life applications, though, that’s not exactly how extra foam in your kayak works.

No, foam inside of your kayak isn’t going to add any buoyancy in most “normal” conditions. You’re not going to find your boat sitting a little higher, your waterline sitting a little higher, or anything like that when you add new foam to the boat.

What you will see, however, is a whole but more buoyancy for your vessel if you start taking on water.

As every kayaker knows, paddling out there in the water (especially when the water is rough or choppy – which can happen on gentle ponds just the same way as it can happen on the ocean, on rivers, etc.) inevitably result in some water getting into your craft.

The extra foam helps to add buoyancy in those situations – sort of the same way that a PFD (Personal Flotation Device) works to keep you afloat if you fall in the drink.

Improved Recovery

Thanks to the improved buoyancy, your kayak isn’t going to sink like a stone straight down to the bottom of the body of water that you are paddling in when you have filled it with a bit of extra foam.

A “raw” kayak that hasn’t been modified this way is going to be pretty heavy when it starts taking on water. It doesn’t take long for a capsized kayak to scuttle and sink.

If that happens, you have to either spend a lot of time (sometimes a lot of money) to recover your kayak or consider it a total loss and buy a new one – which is also pretty expensive, too.

The increased buoyancy of extra foam in a kayak helps your vessel sort of sit in the water even if it takes on a lot more than it was designed to. It might sink a little below the surface of the water, but it’s going to sit and kind of hover there (or delay the plummet to the bottom long enough for you to recover it).

What Kind of Foam Should You Use in Your Kayak ?

There are a lot of different options available to you when it comes to putting foam inside of your kayak, but you want to make sure that it’s a specific kind of foam – one that isn’t going to soak up water, make your boat even heavier, and push it deeper (and faster) to the bottom.

Cross-linked polyethylene foam is a fantastic option. This is the kind of foam that they make pool noodles out of, and it’s a reasonably easy kind of foam to get your hands on.

Another added benefit of this kind of foam is that it’s going to be really soft and comfortable up against your skin. One of the reasons people rip Styrofoam out of their kayaks has to do with the fact that it is so uncomfortable, especially when things get hot, sweaty, or wet.

You don’t have to worry about that with cross-linked polyethylene foam material!

Other things to look for in foam you’ll stuff inside your kayak include:

  • Higher buoyancy ratings
  • Low water permeability ratings
  • Durability and resilience, especially when exposed to water and UV light
  • Resistance against mold, mildew, and rot
  • Easy ability to absorb shock and not deform or separate

Square that away and you’ll be good to go!

Closing Thoughts

So there you have, the perfect answer to whether or not you can fill a kayak with foam and if it’ll have any real impact on the performance of that boat out on the water.

Yes, you can (and probably should) add a bit of foam to the cabin and bulkheads of your kayak. Especially if you’re going to be paddling out in rough, choppy, or fast-moving water.

You just have to be sure that you’re using the right foam. Leverage the tips and tricks we shared above and you won’t have any trouble finding that, though!

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