Why Are Pontoon Boats Not Suited for Offshore Angling?
By Frank Sargeant
from The Fishing Wire

I love pontoon boats. In fact, I’d have to say of all the boats I’ve owned (20-something at last count), the 22-foot pontoon was my favorite–just a truly comfortable multi-purpose rig that worked fine as a one-man (plus dog) fishboat on many foggy dawns, but could then be loaded up with a dozen family members on the weekends and function as a towboat, picnic barge and general muck-about.

And there are now larger pontoons, up to 12 feet wide and 30 feet long, that can handle some serious water. And there are lots of pontoons that, buckled up to a 300-hp outboard, can take you down the lake at 50 mph. There are even a few that accept twin V6 outboards for even higher speeds.

That said, one of the places that pontoons do not belong is 6 miles offshore in the Gulf of Mexico, which is where the Coast Guard found a 24-footer half sunk with six anglers aboard this past week, west of Sarasota, Florida. Everyone got home safe thanks to the rescue team, but the outing could easily have had a much more unhappy ending.

Because of their design–two or three aluminum pontoons supporting a completely flat deck extending from bow to stern–pontoons can get in serious trouble in rough water. The air-filled pontoons give the boats buoyancy, and they can ride up and over waves up to maybe 3 feet tall, depending on their frequency–lots of sharp, steep 3-footers are not survivable in most pontoons, while long rollers can be ridden out.

But even the biggest pontoons have very little “freeboard” compared to the typical vee-hull boat or offshore catamaran. Many vee-hulls designed for regular offshore use have a forward depth over 40 inches, while the largest pontoons are usually under 24 inches from the deck to the waterline.

What’s more, pontoons do not have bilge pumps–if they get a hole in the compartments of the aluminum sponsons, that compartment can fill with water. The several sealed compartments in each pontoon will keep the boat afloat, but particularly if the hole is in a bow compartment–which is most likely because that’s the section of the boat that takes the brunt of the wave action as well as experiencing lots of wear and tear from grinding up on a gravel beach or bumping a dock–the boat may start to go “head down”, making her even less sea-worthy in rough water.

Pontoons seem impossibly stable in most conditions because of their widely-spread sponson design–they hardly lean to port and starboard at all, as do conventional vee-hulls. This tends to give users a sense of security that’s not really there when the boat gets in truly rough seas.

And when green water starts coming over the front deck, things can go south immediately; the boat becomes impossible to steer, drops off plane, and is likely to tilt to one side or the other as the water tries to get out.

I speak not from offshore experience in pontoons–I never took mine outside the inlet–but from wake-eating experience; on a couple of occasions I was careless enough to run head on into a steep, rolling wake of a big ICW-cruising yacht. In one case, the wave actually broke the windshield off the console and sent it into my lap. You’d think that would have been an adequate warning, but a couple years later I again stuck the nose and soaked everybody up front, though with no boat damage.

This same sort of steep roller is common in inlets everywhere, particularly where wind and tide oppose. And an inlet that’s a pussy cat on the way out, with wind and tide both heading seaward, can be a snarling monster on the way back when the tide is coming in and the wind is blowing hard against it, or vice versa. It’s no place for even experienced skippers in small boats–a weekend captain in a pontoon can get in deep trouble quickly.

In short, pontoons are lovely family boats on the lakes and rivers and most of the bays of America, but they clearly don’t belong offshore, even in temptingly calm weather.