This is such as interesting question, as it’s typically posed by people who are new to pontooning or are considering buying one for themselves.
Can pontoon boats sink?
Yes, of course they can.
But it’s very rare and it would have to be in exceptional circumstances. I’ve never seen it happen in my lifetime and have only read about this happening on a couple of occasions.
The common consensus though, is that pontoon boats are un-sinkable due to the way in which they are designed.
Let me explain.
Manufacturers of pontoon boats baffle the pontoons into multiple air-tight chambers. This gives them an almost un-sinkable buoyancy. The pontoons are then sealed, so unless you rupture one, it’s not going to sink.
And even then, if one of the pontoons is cracked and filled with water, the other pontoon should in theory still keep the entire boat afloat. Only one of the chambers will fill, and the other one will take the remaining weight.
The bottom-line is; it’s massively unlikely and rare that you would ever be able to sink a pontoon boat.
Even if a pontoon boat did start to sink, I find it unlikely that it would become completely submerged due to the buoyancy design.
If a tube did get punctured and started to fill with water, I doubt that the entire deck would go under. Instead what you may experience is some degree of listing to the injured side.
One thing to be careful of though, is that some pontoon boats have pontoon logs with drain plugs in the back of them. If these plugs aren’t secured, then water will fill them up. So, if that applies to your boat, make sure that you check them regularly for damage.
Whilst writing this article, I did actually stumble across a rare photo of a pontoon boat sinking. You can see that image below.
Image copyright of ishoot38, a forum member on winnipesaukee.com.
Notice how the deck hasn’t gone completely under.
What I imagine has happened here is that the people in charge of the pontoon have really given it some punishment and banged it over a load of rocks along the whole of the underside, or the pontoons were not baffled.
Perhaps they were unaware of rocks or other hazards in shallow water. You can read more about pontoons in shallow water in this article.
If for some weird reason the tubes became detached from the deck, then of course, you are going to sink – but I have never heard of that happening in all my years on the water.
But They Can Flip
The more likely scenario with pontoons is flipping. This can occur in very rough and choppy water, which is why I advise you don’t take a pontoon out in bad weather if you are a beginner (or even an experienced pontooners).
Whilst flipping is still unlikely, it can happen when pontoons catch a large wave from a bad angle. Again though, it’s extremely rare, and should not be something to put you off getting into a pontoon.
Conclusion
With the right (or should I say “wrong”) chain of events, a pontoon boat could sink.
But, please don’t worry as the design of the tubes is such that these boats are almost un-sinkable and can withstand huge downpours of rain and other factors but will still remain stable.
Things to look out for which could lead to a sinking include broken welds, punctures, tears, rips, cracks, or even electrolysis which can be an issue. But these factors are the same for any type of boat and are not exclusive to pontoons.
Overall though, pontoon boats are renowned for being safe and a boat that is unlikely to sink.
If you are still on the fence or concerned about buying your first toon, I genuinely don’t believe you should have any concerns. Go out there and start having fun on the water!
