Pontoon Boat & Deck Boat Forum

Saturday I took a family out on the lake for an ashes-spreading ceremony. There were 10 adults on board including me and my logs were almost completely under the surface. I'm going to say that's my practical passenger limit
What happens if I add more weight--does everyone's feet get wet as the boat becomes a raft, or worse?

Do you know what its like to "submarine"?
If you decelerate to quickly your front end will nosedive at the very least-
Not fun for all involved.

guy48065 wrote:Saturday I took a family out on the lake for an ashes-spreading ceremony. There were 10 adults on board including me and my logs were almost completely under the surface. I'm going to say that's my practical passenger limit
What happens if I add more weight--does everyone's feet get wet as the boat becomes a raft, or worse?

Yes everyone's feet get wet.

The tube maintain bouyancy even when fully submerged The problem is that water on deck adds to the load of the boat and eventually will have greater weight than the tubes have bouyancy. When this happens the pontoon will sink until some of the weight is removed.

So lets say you put another 3 adults on there. The weight is suddenly greater than the tubes bouyancy and the pontoon will sink. (of course additioanl bouyancy is supplied by your seats when the water gets that high IF they don't have drains in them).

As you go under water your least favorite brother-in-law (the big cow) dives off and takes two others with him. If the weight removed is enough, the ponton will surface again until the weight on top is in balance with the bouyancy below. Although the carpet's now wet, there may be water in the seats etc, so more weight would need to be removed. But eventually, when enough weight is removed the pontoon will float again. These things are incredibly hard to sink.

It is likely however that as the boat goes down it will tip to the heaver side and dump a bunch of people. It will right itself when it gets back on the water.

Of course if your tubes are open (that is, vented so that water can get into the tubes somehow) then all bets are off.

John O does a great description. It trully is little different than a raft, UNLESS you have a way to collect water weight, in the tubes or elsewhere. Even vented tubes won't take on much or any, as the vents are usually very small and are u shaped at the top (known as a loop seal in my industry).

That said, when you add power to the mix, there are a number of very real dangers to it.
The least of which is the dreaded 'submarine' under power. You can easily take out your front fence and structure. The boat will stop like it had brakes and throw everybody forward. If one of them goes off the bow while still under forward thrust, now you are in danger of running them over
This is very bad, unless of course it is your big cow of a brother-in-law

On my first toon (still with the shack, although the smaller original size of 6x8), it was a leaky steel tube jalopy, the original Al. After a massive resort party with several bands (mine included), we ended up in the shack for a bit of an afterparty (it was cold out and I had heat). We must have had a dozen people squished in there and more on the deck peering whistfully in the windows like shivering birds. Of course there was alcohol involved and I wasn't paying much attention, when I realized that my feet were getting wet. I looked back and saw my 35Merc about 3/4 under water and we had to make some quick adjustments to the weight ratio
Next morning, I had to pull my motor and dry it out before it would start

Aaaand that's when I built Al#2! The rest is history.

I'm kinda scared of what Al the Fourth might look like

So what happens when you overload a pontoon?

You sink...

Also possible that if load or people are thrown to one side the boat could flip

HEY!

I'm the big cow brother-in-law and don't appreciate the bad karma coming my way on here!

Mosnowman wrote:HEY!

I'm the big cow brother-in-law and don't appreciate the bad karma coming my way on here!

I humbly retract any earlier statements and beg forgiveness from Mr. Murphey

It takes a SERIOUS amount of overloading to sink a pontoon, usually the listed capacity is somewhere around 40% of the actual floatation capacity of the pontoon. The REASON for the 40% is encase someone yells "look at the sea monster over here!" and everyone on the pontoon decided to lean out over the railing on one side! The weight listed on the capacity plate is the "over 5mph" weight according to the Coast Guards recommended specs. My Grandpas work barge is an old 30' Ercoa "hex toon" with a 3500# capacity and with proper load placement will handle 5000# with ease and still have 4-5" of pontoon showing BUT the speed stays below 5mph (merc 50hp bigfoot)

I'm glad to hear it's fairly predictable. I was afraid the answer might be "with that much weight above the center of gravity it'll suddenly capsize". I can deal with wet feet but not lawsuits.

Pictures would of been awesome!

Here's one example of what can happen.




Here's another.

BoatCop wrote:Here's one example of what can happen.




Here's another.

Nice shots. One of em makes me nervous tho.
Would that happen to be your boat, Alan?

tuned wrote:

BoatCop wrote:Here's one example of what can happen.




Here's another.

Nice shots. One of em makes me nervous tho.
Would that happen to be your boat, Alan?

Doesn't look like AZ to me...

Nice Submarine!