Are Pontoon Boats Foam-Filled?

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Pontoon boats are popular among the leisure boating community. This is because they are stable and spacious, fun and flexible. Calm waters are ideal for toons, and they should be kept out of rough seas and rocky areas. How do Pontoon boats work? Are pontoon boats foam-filled?

Some pontoons are filled with foam, though most are just filled with plain old air. The foam doesn’t help with buoyancy, but it could help if there was an accident and a puncture.

We’ll go over the details of all this below!


What’s Inside the Pon-tubes?

Most Pontoon boats have hollow aluminum tubes, filled with air. There’s no need for any additional foam or extra floatation, as the air provides enough buoyancy to float with nothing else to worry about.

That said, you may also come across other pontoon designs that aren’t fully foam-filled, including air-filled tubes and chambered tubes.

Here are the different tube designs you will find used in pontoon boats:

  • Chambered tubes
  • Foam-filled tubes
  • Air-filled tubes

The hollowness of the tubes increases the buoyancy, which aids in water displacement.

Are Pontoon Boats Foam-Filled? Types of Tubes in Pontoon Boats

Now let us review the different types of tubes in current pontoon boats. This is to give you a better understanding of a shaped pontoon.

1. Air-Filled Tubes

One of the tubes you will find in a pontoon is the air-filled tube. Of course, all inflatable pontoon boats are designed with air-filled tubes, but many solid toons use air-filled tubes as well.

Many manufacturers prefer to leave the pontoon tube airless. As mentioned above, filling them with air will have zero effect on buoyancy. This means that internal air will not stabilize the boat or make it float better than if it was foam-filled.

This may sound strange! Why have pontoon chambers if the air doesn’t help? The answer is that it doesn’t help or hurt, relative to foam.

This is generally the cheapest option, and most manufacturers don’t want to spend money unnecessarily and make their boats cost more than the competition.

However, if there was a large puncture in the tube and water started to get in, this could lead to the failure of the pontoon structure, and eventually to capsizing or sinking of the pontoon boat.

In order to prevent this circumstance, some manufacturers fill their tubes with foam.

2. Foam-Filled Tubes

Foam Filled tubes are also common in pontoon boats. Just like with air-filled tubes, foam-filled ones have little or no effect on buoyancy. Foam doesn’t make the boat function any better.

But there is a reason why they have foam in the toon tubes.

The foam-filled tubes help the vessel float better when submerged in water. Floatation occurs with water displacement. A floating boat is an indication that the vessel is above the waterline.

If there is a puncture in a foam-filled pontoon, there won’t necessarily be as much water infiltration because the toon is already filled with foam. Water can’t get in as easily as it would if it was just air-filled, so it will last longer before sinking.

3. Chambered Tubes

Another common design is chambered structures divided into several sections. These tubes have different compartments, some filled with air, some filled with foam.

Chambered tubes are used because of safety reasons. If a hollow tube starts leaking, it becomes heavy. This is because water gains entry which leads to reduced buoyancy.

If left unchecked, this can lead to sinking or cause the boat to nosedive. Even the smallest leak can be dangerous if ignored. But with chambered tubes, the water infiltration will be limited to a small section. This is because of the different chamber separations.

Even the smallest leak can be dangerous if ignored. But with chambered tubes, the water infiltration will be limited to a small section. This is because of the different chamber separations.

How Do Tubes in a Pontoon Boat Work?

We have explained the different tubes in a pontoon boat and what they are designed for. Now, let us explain in detail how the tubes in pontoon boats work.

The essential purpose of having tubes in pontoons is to cause floatation and buoyancy. Famously, Archimedes stated that objects would float if their weight displacement across the water is equal in weight.

Water displacement refers to water that is moved to make room for the object that takes its place. So what keeps a pontoon boat afloat?

It is not simply the foam-filled tubes but the weight and shape of the boat. This allows it to sit and move in water with its weight. So the lighter the boat is, the further away it is from the weight of water. But the heavier it is, the closer it is to the weight, which may lead to less buoyancy.

So here is the takeaway from pontoon boat tubes.

  • Foam-filled air will not make the boat float better, so tubes are largely hollow
  • Filling the tubes with air is easiest, but there is a risk of sinking if punctured
  • Using chambered tubes protects the entire tube from getting compromised if there is a leak


There are three common pontoon designs: air-filled, foam-filled, and chambered. The material inside the pontoon does not matter when it comes to floating capability. These aspects really only come into play if there is a puncture and a leak.

Remember that most pontoon boats do not have bilge pumps, so if you get a leak you want to get back to the dock or the boat landing ASAP to get it taken care of, particularly if your toon is filled with air!