Consequences of overpowering a dinghy?

[ranger58sb]

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.

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

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.

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.

Our Walker Bay Genesis comes in two versions, too, one tiller and 15-hp max, one wheel and 20-hp max.

WB told us it was about increased weight, different placement of load, etc... as others have 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...

Could be, especially given many are sitting on the tubes with a tiller-steered dinghy... but "inside" at a console. OTOH, WB's story was all about load weight and load placement.

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.

Used to be different, in that 10/15-hp 2-stroke motors were built on a shared platform, 20/25-hp outboards on a larger shared platform, etc...

But more recently 8/10-hp, 15/20-hp and 25/30-hp outboards have shared their respective platforms...

Suzuki adding their 9.9 to the 15/20-hp platform seemed a bit odd, to me...

Anyway, yes, running the 20-hp version at the same RPMs of a 15 would seem easily possible, but I'd guess it's not difficult to exceed those RPMs even if by "accident"...

But then I'd also guess all the cited downsides to "over-powering" would still apply if something happened to cause deeper investigation.

-Chris

 

[smitty477]

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.

Which exact RIB and which exact Yamaha 70 are you considering?
Have you been on the Yamaha performance bulletin sites to see what the boat may run like with rated hp?

 

[hollywood8118]

Both of my dinghy's are over the rated hp, our console rib Avon is rated for 25.. it has a 40, our air floor Zodiac is rated 9.9 it has a much beloved 2 stroke 15. The least of my worries is getting cited. the Avon is overpowered.. the dam thing tops out with me solo a tad bit over 40!. The Zodiac feels right. If one abuses the extra HP and thrashes a dink that is over HP then it could most likely lead to issues.



Roll the throttle on responsibly and dont drive like a bonehead in a little over hp shouldn't be a issue.


If your a moron and are in the camp that " I should be able to do anything to it and it wont break or kill me" it's probably smart to stick with the rated HP.


Buy the way.. my kids did use both boats in their adolescences with strict instruction to go easy on it or" it will hurt you".. they both survived.


HOLLYWOOD

 

[Mrwesson]

Take the cap plate off and it's likely they will completely ignore that you don't have one(I don't have one on my boat and never been asked about it/dozens of stops).

Or you can legally make your own .

Boat Building Regulations | Boat Warning Labels

Legalities vs liability is muddy and each state has their own statutes so i'm not going to say it's legal everywhere.

You could also just swap the cowling to a lower hp or just take the stickers off.. If they can cite you then at least don't make it easy for them.

I have a 90hp outboard that lost a lower unit/broke a midsection so I used a 75hp midsection/lower(same thing/same company). The serial number says 75 and the cowling says 90 with a 90 powerhead. Totally legal.

You can put a different carb on some tillers to add hp to the next level... The whole thing is stupid.

People getting worked up will probably tell you the FBI will come for you if you take the tag off your mattress.

 

[smitty477]

"Take the cap plate off and it's likely they will completely ignore that you don't have one(I don't have one on my boat and never been asked about it/dozens of stops)."

Perhaps where you are - do not come up here and expect the same.

 

[boatpoker]

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.

In Canada "Capacity Plates" are law for certain size vessels. Not sure the insurance companies pay out on illegal activities.

 

[Alaskan Sea-Duction]

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

Ted

Hey wait a minute!! That could be me and Crusty!!! Hold my scotch Crusty would you please??

 

[Group9]

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."

I guess the safest thing is to just never let them out of the house.

 

[DDW]

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.

Yet this is simplistic enough to be idiotic.

On the Bullfrog, the seat for tiller steered and wheel steered is in exactly the same place, and is exactly the same seat (they simply add a seat back). Weight distribution is what it is, and can be the same in either configuration. It is actually more likely that the weight is further back in the wheel steered, as two people are going to sit behind the wheel, while on the tiller version one will be on the forward seat.

If you don't want to change the placard, there is another solution: buy a new decal for the motor cover. In the Bullfrog case, since any of the big 3 motors are identical between 10 and 20 hp (but for the throttle stop), simply put a 15 hp decal on the 20 hp motor and you're good to go. It would take an engine mechanic with the ability to read out the ECU version to prove you wrong.

 

[smitty477]

I guess the safest thing is to just never let them out of the house.

I don't think so - we let our kids out all the time. We just taught them as best we could including to follow the laws.

 

[Group9]

I don't think so - we let our kids out all the time. We just taught them as best we could including to follow the laws.

The hard part isn’t following them, the hard part is knowing all of them.

 

[smitty477]

Yet this is simplistic enough to be idiotic.

On the Bullfrog, the seat for tiller steered and wheel steered is in exactly the same place, and is exactly the same seat (they simply add a seat back). Weight distribution is what it is, and can be the same in either configuration. It is actually more likely that the weight is further back in the wheel steered, as two people are going to sit behind the wheel, while on the tiller version one will be on the forward seat.

If you don't want to change the placard, there is another solution: buy a new decal for the motor cover. In the Bullfrog case, since any of the big 3 motors are identical between 10 and 20 hp (but for the throttle stop), simply put a 15 hp decal on the 20 hp motor and you're good to go. It would take an engine mechanic with the ability to read out the ECU version to prove you wrong.

As I said before you an do whatever you want and have no affects unless you have an accident and/or get caught.
Boater on Sleepy Hollow lake did just what you said - ad an accident, got caught, paid many 5 figures in damages and fines.

In the end the boats rated for less Hp very often run poorly when over powered.

 

[smitty477]

The hard part isn’t following them, the hard part is knowing all of them.

Maybe - but certainly in this case we do know the rules and if in doubt we have plenty of LEO's in the area to ask.

 

[Crusty Chief]

Hey wait a minute!! That could be me and Crusty!!! Hold my scotch Crusty would you please??

Cuz your dink is faster than mine.

 

[Delfin]

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.

True. My friend Pete and I used to tool around in a 10' boat with a 50hp Merc on lake Washington. As I recall we could do around 60.

 

[firehoser75]

Personally I think this all comes down to your "risk" tolerance!!
Firstly, how far over the rating are you willing to go in your engine selection?? How do you determine this "rating" if you don't follow what the manufacturer states? How big is tooo big?

In TT's case, being only over by 10hp (17%) and already owning the engine, from strictly operating safely, probably would be OK, especially operated by a responsible, safety minded individual.
However, are you willing to risk no insurance coverage (denial of claim), potential criminal charges (don't know the law in this area and it probably varies by location), and personal financial liability for damages should an accident occur? It could happen, but very unlikely. Are you willing to take the risk? Some are, some not so much.

For example, I know of a case in the eastern US where a boater was anchored for the night, had on his anchor light, and a drunk boater collided with his anchored boat. They spent 2 days at trial discussing whether or not his anchor light met US Coast Guard regs as he had substituted an LED bulb in a light fixture that originally was rated with a regular bulb. Apparently the rating is for the entire fixture including the bulb and does not allow using a different bulb type (otherwise, it would have to be "recertified"). This was the tactic employed by the drunk boater's lawyer. Apparently the issue wasn't the fact that the fellow was drunk, it was whether or not the light was bright enough or whether it met the "rating". Go figure!
Just my ramblings on this interesting topic,
Tom

 

[markpierce]

Looking over the railing, watching the water pass while going six knots, seems pretty fast for this old sailor. Am not a fan of loud engine noise.

 

[GFC]

https://www.ebay.com/sch/i.html?_fr...acity+.TRS0&_nkw=boat+capacity+plate&_sacat=0


Why not just go to ebay and order a new capacity plate with whatever numbers you want on it?

 

[healhustler]

Twisted: Now that I see the increase your speaking about, I’d change out the engine decal, as suggested above. Going from 60 to 70 HP considering the data you mentioned hardly seems unreasonable unless it’s an awfully heavy 70. If I had the motor, I’d do it.

 

[Wxx3]

...
If you're a moron and are in the camp that " I should be able to do anything to it and it wont break or kill me" it's probably smart to stick with the rated HP.

HOLLYWOOD

Until I see real data, I believe the rated hp doesn't keep morons any safer. They will still hurt themselves and others at any hp.

Beyond an advisory role (whichis useful), these hp ratings and limitations are more of a bureaucratic reason to exist than anything else.

Keeping us safer? Keep dreaming.

 

[smitty477]

Until I see real data, I believe the rated hp doesn't keep morons any safer. They will still hurt themselves and others at any hp.

Beyond an advisory role (whichis useful), these hp ratings and limitations are more of a bureaucratic reason to exist than anything else.

Keeping us safer? Keep dreaming.

Kinda like - only the rules that you deem appropriate apply to you maybe.

 

[Mrwesson]

"Take the cap plate off and it's likely they will completely ignore that you don't have one(I don't have one on my boat and never been asked about it/dozens of stops)."

Perhaps where you are - do not come up here and expect the same.

Then swap a cowling or make another capacity plate yourself.

 

[smitty477]

Then swap a cowling or make another capacity plate yourself.

Please see the post about the fines/damages when they did just this on a lake in NY.
If you choose to ignore laws and rules please do not complain if/when those around you do the same.

 

[koliver]

For example, I know of a case in the eastern US where a boater was anchored for the night, had on his anchor light, and a drunk boater collided with his anchored boat. They spent 2 days at trial discussing whether or not his anchor light met US Coast Guard regs as he had substituted an LED bulb in a light fixture that originally was rated with a regular bulb. Apparently the rating is for the entire fixture including the bulb and does not allow using a different bulb type (otherwise, it would have to be "recertified"). This was the tactic employed by the drunk boater's lawyer. Apparently the issue wasn't the fact that the fellow was drunk, it was whether or not the light was bright enough or whether it met the "rating". Go figure!
Just my ramblings on this interesting topic,
Tom

Another example of the silliness of some litigation. Some places allow frivolous litigation to go ahead with little or no consequence to the silly party. Your example is just that. No idea shown of the actual result, which undoubtedly has a far greater penalty for the drunk behaviour that for the "innocent" behaviour re the light.

Here in Canada (not saying our whole legal system is better) there are significant extra costs to bringing or continuing with silly litigation, so we don't see near as much that makes you wonder.

 

[alormaria2]

It goes on your permanent record.

 

[FlyWright]

My last dink was a 9.5 ft Achilles with a wood floor and inflated keel on 15" tubes. It was rated for 8HP and I started operating it with a Honda 2HP. When I acquired a Merc 2-strike 15, I tried it out on the dink for fun. It's the same engine platform as the old Merc 2-stroke 8 and 9.9 HP models. They each weigh the same 77 Lbs.

It was a handful! It felt like I was driving a sheet of plywood on an ice rink! I took off the Whale Tail and it improved a bit but was still very unstable over 2/3 throttle, so I nursed it along for a while and took it carefully. It could be a wet ride at times.

Last year I purchased a 10' 10" (3.3m) dink from Costco for under $500 that's rated for 15hp. It still has a rigid floor (aluminum) and an inflated keel but has 17" tubes and almost an extra foot of beam. This dink is rated for 15HP. It's a world of difference in stability, handling and dry ride.

I enjoyed testing the waters with an over powered dink but in the end, this setup is the best fit for me. I've put my 2HP up for sale in the classifieds if anyone is interested in a great running 2HP Honda.

 

[cardude01]

That $500 Costo dink sounds like a serious deal! I paid waaaay more for my West Marine 310 with the fiberglass floor, and it was on sale.

 

[FlyWright]

That $500 Costo dink sounds like a serious deal! I paid waaaay more for my West Marine 310 with the fiberglass floor, and it was on sale.

I love this dink! It was one of my best $500 purchases for the boat.

 

[twistedtree]

Thanks for all the discussion.


It would be easy to hide the over-powering with a different cowl or such and not get fined.


But the real risk is if there is actually an accident - not me being drunk or an idiot, but an accident, because they actually do happen despite all good actions. Insurance contracts all have clauses about breaking laws, falsifying info, etc. If the boat were over-powered, it could nullify my liability insurance, and my excess insurance, leaving me totally exposed. That's way too much risk, because I know shirt does happens, and it could wipe me out.


The only way I would do it is if I could legitimately re-certify the boat to a higher HP capacity, given a fixed console and steering system. I think AB has just chosen not to do that where other vendors have. I mean come on, Arthur's 11' dink is rated for 50hp and my 15' is rated for 40hp? So I'll probably continue to explore this approach, looking for a legitimate re-rating, not a way to get away with something.


And by the way, I don't agree that these are just bureaucratic nonsense rules to keep the Coast Guard in business. If you read the regs, a lot of thought clearly went into them, much like all the other boat safety regs.

 

[Insequent]

TT
Sounds like you are looking at an AB 16' Lamina. As much as I like my 14' Lamina, if I were in your position I would look at alternative brands of RIB. eg Zodiac Pro 500 is just short of 16' and is allowed max. of 70HP. Like you I would not exceed manuf. specs for a bunch of reasons.