Offshore is No Where for Pontoon Boats
By Frank Sargeant, Editor
from The Fishing Wire

The Coast Guard assisted a sinking pontoon boat off Holmes Beach, Florida, this past weekend, bringing to the fore the boom in these popular and very family-friendly watercraft, but also their limitations. The boat was 12 miles offshore and taking on water. Twelve miles offshore, in a pontoon boat!

Because pontoons are no longer necessarily sub-20-mph vessels thanks to triple pontoon designs, larger tubes, planing strakes and beefed up transoms that can handle 300 horses and more, a portion of the thousands who are buying them these days come to think of them as potential open water and even offshore fishing machines/cruisers.

And while the larger models–some are 30 feet long and 12 feet wide these days–are definitely far more seaworthy than the classic 22-footer with an 8-foot beam and two small pontoons, they are definitely not capable of dealing with rough inlets, nor with the big rollers that sometimes build rapidly offshore in storm conditions.

And they can’t run home rapidly when things start to go south–most of the time, before a pontoon can get back, seas will have built to the point that running at speed is impossible. This is true even in deep-vee monohulls designed for offshore travel–in a pontoon boat–even one capable of 50 mph in flat water–it happens very fast.

Pontoons are incredibly stable in flat water, which tends to give us (I’m a long time ‘tooner) a sense that they will be that way in rough water. But, while pontoons do great in little 1 to 2 footers, when the seas get tall enough and steep enough to start slopping over the bow and up on the deck, you’re already in trouble.

The front of a pontoon boat is vertical and flat, just exactly what you don’t want to have to stick into an on-coming roller–that’s why real offshore boats have a “pointy end”, a bow with what designers call a sharp “entry” designed to split the waves and lift the bow over them.

While the pontoons provide lots of lift and will ride over some considerable seas at low speeds, they will simply stuff the nose of the boat into a wall of water at some point where seas too tall and speed too great converge. The front “fence” or railing likely will be swept back into the boat, and several tons of water will come surging in on the deck. Fortunately, it will run back out pretty rapidly on most designs, but if a second wave hits before the deck has cleared, the boat may very well decide to roll, or may at least squat so far aft as the weight shifts that the motor sucks in water. Without power in rough seas, most boats don’t last long.

Even big inland lakes can overcome a pontoon in some conditions, though ‘toons are pretty much as seaworthy as most boats designed for inland use. The idea there is just to be aware that some weather is simply too much for most recreational boats, and that if you have any doubt whatsoever about how safe your boat will be in the conditions you’re likely to face, you don’t venture into open water.

To be sure, I’m not saying that larger pontoons should never venture outside an inlet–those riding on large triple pontoons can handle riding through passes and down the beach or crossing big open bays without problem in good weather. (Be aware, though, that wakes from large yachts and commercial boats can give everybody aboard wet feet or worse if you hit their wake wrong.) But heading 10 miles or more offshore in a recreational pontoon of any design is never a good idea.

Fortunately, these days in most areas, there’s no reason to let the weather catch you by surprise–just ask Siri or Cortana anytime you have doubts, and check the weather radar on your phone or your GPS, if properly equipped, regularly, particularly if you see clouds approaching.

Pontoons are wonderful family fishing and boating platforms, probably safer than most other types of boats, and certainly more comfortable–they have converted tens of thousands of non-boating families to boat lovers in recent years. But knowing their limitations before you leave the dock for the first time, or the hundredth, is a must.