Consequences of overpowering a dinghy?

In another thread the topic of overpowering a dinghy came up. Rather than hijack that thread, I though I'd start a new one.


Small boats all have a sticker in them listing max load and power capacities, but I have no idea what law or regulation those are based on, and who cares.


So if the sticker on my boat says 40hp max, and I put a 50hp on it, what happens? Will the Coast Guard ticket me? Or maybe the local law enforcement types? Will an insurance company not insure it? How would they even know what the HP limits are for the boat?


Who actually cares, and does it really matter? I intentionally picked the numbers In this example because it's not massively over powered, and not a much heavier engine, which I think would be the obvious Darwin moves that someone could make.

I am not a lawyer but I believe the term is prima facia evidence of negligence. Your insurance will probably be void and you will get cited if LE catches you. But other than that what’s the problem.

Yes, your voyage can be terminated .yes, LEO do sometimes check the capacity plate, definitely if it is not just a random boarding as in accident.

While against the law, especially state laws in particular, but I am not sure what the penalties are.

Likely a fine, maybe in states with safety certificates some sort or revocation.

Cmon, be a rebel. ��

The LEO's in our harbor will occasionally check and they will ticket you.
Your dinghy warrantee will be voided.
If you have an accident involving someone else your situation will become complicated quickly.

And if none of this happens you will likely just have a poor performing RIB due to weight and/or Hp.

This seem to me to be kind of an overreach though a bit of web time found there is an actual performance test to determine max HP ratings.

33 CFR 183 Subpart D | Boat Safe Horse Power | New Boatbuilders Home Page

Boat Building Regulations | Safe Horsepower For Outboard Boats

The second link notes the following - "The below formulas do not apply to: sailboats, canoes, kayaks, and inflatable boats, that are designed or intended to use one or more outboard motors for propulsion. It does not apply to boats that are true multihulls. A multihull makes two or more separate footprints in the water. A pontoon boat is a multihull."

Personally, if I had a 50hp and the max was 40, I think I'd find a new decal...

Have a mishap that involves the ColRegs and you will find yourself charged likely with traveling too fast for conditions, then your insurance will find that your negligence was responding responsible for the mishap. Secondly engine hp is dictated by the mfg to ensure that their craft are stable and safe. Once again mfg liability is negated. Last point deals with load. Once again all craft so annotated are built to support, horizontally, the load so annotated. That includes the engine. So putting a large stat the stern if filled with H2O likely will result in a vertical position.

Do it! [emoji51]

https://youtu.be/CXWPttkArh8

I have a Bullfrog 10'. The placard says 15 hp max. Bullfrog sells a version with a steering station and seat, the placard on it says 20 hp max. I enquired, they said the boats are identical, but the CG allows them to put a 20 hp placard on a boat with a wheel and seat. The steering wheel and seat can be installed or deinstalled with a couple of bolts.

So what's it based on? Not much, I'd say.....

cardude01 said:

Do it! [emoji51]

https://youtu.be/CXWPttkArh8

Click to expand...

They don't need no stinkin' lawyers.....

MRRiley said:

This seem to me to be kind of an overreach though a bit of web time found there is an actual performance test to determine max HP ratings.

33 CFR 183 Subpart D | Boat Safe Horse Power | New Boatbuilders Home Page

Boat Building Regulations | Safe Horsepower For Outboard Boats

The second link notes the following - "The below formulas do not apply to: sailboats, canoes, kayaks, and inflatable boats, that are designed or intended to use one or more outboard motors for propulsion. It does not apply to boats that are true multihulls. A multihull makes two or more separate footprints in the water. A pontoon boat is a multihull."

Personally, if I had a 50hp and the max was 40, I think I'd find a new decal...

Click to expand...

The CFR is interesting, with one key distinction being a remote vs tiller steering. Makes me wonder if the ratings assume a tiller, and would be different for boats rigged with a console and remote steering....?

I think remote steering is significant because it moves the weight of the driver to the center of the boat.

Doesn't the registration contain information about the size and make of engine ? Would changing the engine void your registration ?

Just order the HP sticker you need and change it out on the engine. Pretty easy thing to do. A buddy of mine did this so he could travel up the Colorado below the Hoover Dam for fishing spots. Never got caught and he did catch a few big ones he hunts for. Just dont ask him, those damn fish have grown substantially over the years.

DDW said:

I have a Bullfrog 10'. The placard says 15 hp max. Bullfrog sells a version with a steering station and seat, the placard on it says 20 hp max. I enquired, they said the boats are identical, but the CG allows them to put a 20 hp placard on a boat with a wheel and seat. The steering wheel and seat can be installed or deinstalled with a couple of bolts.

So what's it based on? Not much, I'd say.....

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Weight mid-ship is the difference and all recorded as part of their testing.

If you remove the weight, then you need to move to the lower HP.

If you don't then, you reconfigured the product they sold you, without reconfiguring the max hp. So now down to you.

Don't do it.

menzies said:

Weight mid-ship is the difference and all recorded as part of their testing.

If you remove the weight, then you need to move to the lower HP.

If you don't then, you reconfigured the product they sold you, without reconfiguring the max hp. So now down to you.

Don't do it.

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Yes - agreed. The rating is made based upon the stability of the boat and the loading with standard and max load. When the steering station is moved fwd the load is moved as well.

Thought I heard (or read) at some point that difference in HP rating for the steering station vs. tiller configuration is due to the inherent instability on a shorter platform should one lose grip on the tiller at higher throttle settings...

Anybody ever hear or read this?

I may have just dreamt it.

What is interesting to me is the negligible motor weight difference. Recently bought a new Suzuki outboard for my dinghy. With in the same model class they have 9.9, 15, and 20 HP. They all weigh the same when configured in the same way. Only difference is top end RPM as limited by the engine computer. So in essence, if you run the 20 HP at 300 or 400 RPM off wide open, you have a 15 HP, same weight, same RPM. Other than the engine decals, there's no apparent difference at that RPM.

Ted

Flybull said:

Thought I heard (or read) at some point that difference in HP rating for the steering station vs. tiller configuration is due to the inherent instability on a shorter platform should one lose grip on the tiller at higher throttle settings...

Anybody ever hear or read this?

I may have just dreamt it.

Click to expand...

Yes, I have......And experienced it in small craft many times

As teens, long before anyone thought we should see regulations of this sort, "for our own safety", we did the small hydroplane thing. Some kids in a 10' platform got lots of hp, resulting in lots of speed, no stability, some spectacular flips. No issues with enforcement, insurance, what have you.
Simpler times.

koliver said:

As teens, long before anyone thought we should see regulations of this sort, "for our own safety", we did the small hydroplane thing. Some kids in a 10' platform got lots of hp, resulting in lots of speed, no stability, some spectacular flips. No issues with enforcement, insurance, what have you.
Simpler times.

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We rode the rivers in our jonboats with outboards from ten years old on back in the day. Our parents would be in prison and us in foster homes today.

I didn't spend a lot of time, but did look for anything that said it would be a crime or infraction for exceeding that sticker hp rating and could not find a thing. Might be there but not obvious. As for whether it would void your insurance coverage....not likely at all. Insurance coverage is an entirely different ballgame than whether you're committing some sort of technical offense. Hence why the carriers still have to provide coverage if you're drunk or speeding in an accident.

At least for my concerns of overpowering, my lightweight Caribe 9 would barely support the two cycle 9.9 with my modest 250 lbs,, and would easily swamp on any rapid deceleration with a 9.9 four cycle. Max HP rating was 15, I think. My current Walker Bay RIB is 8’10” and is rated at 10 HP, but the folding transom looks much more suited for the 2.3 Honda I’m using instead. I tried the 9.9 but it squats worse than the Caribe and the transom isn’t as tall or as thick. It’s hard to believe you could be overpowered with a 15, but in these smaller dinghies, I can see the potential danger.

cardude01 said:

Do it! [emoji51]

https://youtu.be/CXWPttkArh8

Click to expand...

Wow that was really cool. I've never seen a boat riding on its propeller. Like something out of a James Bond movie.


Hope he's wearing a life jacket for when he eventually flips.

Crusty Chief said:

Just order the HP sticker you need and change it out on the engine. Pretty easy thing to do. A buddy of mine did this so he could travel up the Colorado below the Hoover Dam for fishing spots. Never got caught and he did catch a few big ones he hunts for. Just dont ask him, those damn fish have grown substantially over the years.

Click to expand...

Only Navy would know how to do that!!!!

cardude01 said:

Do it! [emoji51]

https://youtu.be/CXWPttkArh8

Click to expand...

What could possibly go wrong. Surprised the video didn't start with, "Hold my beer and watch this".

Ted

One might get away legally with a piece of tape on the throttle and a MAX line drawn.

The max line would be the engine de-rated for US waters.

Throttle position is controlled by the boat captain.

Normal on aircraft and choppers.

Yes, but how many kids were killed or maimed compared to today. Just because you survived doesn't mean others were as lucky. Plus there are many more boaters on the waterways today than "yesteryear."

MRRiley said:

Personally, if I had a 50hp and the max was 40, I think I'd find a new decal...

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Yes!
A man with a plan.

menzies said:

Yes, but how many kids were killed or maimed compared to today. Just because you survived doesn't mean others were as lucky. Plus there are many more boaters on the waterways today than "yesteryear."

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I wonder?

Having a steering station appears key to the max HP rating. Some RIB vendors have different ratings for tiller vs console steered boats. But others don't, including AB. The CG regs, which BTW are federal laws, stipulate a formula for max HP rating, and it's different for steering station vs tiller. So that's wy those boats are different.


I suspect in the case of AB, they are just lazy and spec the hull without regard for the installed steering. Perhaps on request they could correct that.


I appreciate all the comments, including the fun ones. I'm pretty conservative when it comes to breaking laws and risk exposure for boating, which is inherently risky to begin with. So even though one could pretty easily get away with having a larger motor, especially if incognito, I agree you would be very exposed if there ever was an accident.


What's behind this is that I'm considering a tender for our boat that has a max rating of 60hp, and that's the same for the open vs console version of the boat. But I have a brand new, never started Yamaha 70 on another boat that I'd like to use.


When I run the CG formula on the open boat, I get 60hp as the max. No surprise there. But when I run the formula on a console variant, I get well over 100hp (I think it was 115hp). That says that if the boat were accordingly rated, a 70hp would actually be a very conservative powering for that boat.