exceeding inflatable outboard hp rating

[Nicholson58]

Originally Posted by Jammer

Inflatable boats are exempt from the formula and can have any rating, or no rating at all, at their manufacturer's discretion, as are sailboats, canoes, kayaks, multihull boats, and (as you point out) boats over 20'.

Ya - Baby!

[flyingfin]

They never check for important items like that,,,,,,,,, but if Barney Fife water cop sees a flare that is one month over date, you get a ticket!

[Nicholson58]

Originally Posted by flyingfin

They never check for important items like that,,,,,,,,, but if Barney Fife water cop sees a flare that is one month over date, you get a ticket!

You should sail the Caribbean. No cops, no inspections, no oversight. About 1/4 of the dinghies at night have no lights and nobody has a PFD. Most dinghies have no anchor or oars. We often see dinghies with up to 8 passengers including children and no PFD. Flairs? Hahahahahahahaha

[Jammer]

Originally Posted by a64pilot

Where does it say RIB’s are exempt?

In 33 CFR 183.51. That's the exemption from the horsepower requirement.


There are similar exemptions for the safe loading rules in 33 CFR 183.31, from being required to have a capacity plate in 33 CFR 183.21, and from the flotation requirements in 183.101, 183.201, and 183.301.

What do you mean by inflatable boat, and where are they exempted?

As far as I know, there is no definition for an "inflatable boat" in the CFRs. Do you believe the term is unclear?

[mikedefieslife]

Originally Posted by Nicholson58

You should sail the Caribbean. No cops, no inspections, no oversight. About 1/4 of the dinghies at night have no lights and nobody has a PFD. Most dinghies have no anchor or oars. We often see dinghies with up to 8 passengers including children and no PFD. Flairs? Hahahahahahahaha

Same as the Med. Especially the Spanish, I've seen 1.8/2.1m dinghies with 5 people onboard with a chinese propane powered engine, with water coming up to the handles on top of the tubes.

Then on their main boat it's usually 1 person per metre.

[s/v Jedi]

We have had coastguard inspections in both Venezuela and Colombia. Dates were checked.

[Ike]

As a coast guard engineer who spent many years enforcing recreational boat standards for manufacturers I'll add my two cents.


Jammer is right. In the USA the hp standard in the Code of Federal Regulations does not apply to inflatables. And yes the Coast Guard has a definition for inflatable. I'm not quoting, just doing it from memory but it goes, a vessel that derives its principle bouyancy from air inflated chambers. This includes inflatables and RHIBs,

And others are also right in pointing out that in some states it is illegal to exceed the values on the label. So why does an inflatable even have a hp rating? They do because most boat manufacturers in the US follow ABYC standards, and there is an ABYC standard for rating HP on inflatables. It is, as some have said, based on length times width etc but uses a different formula than that for regular outboard boats.

Also insurance companies do look at HP ratings when considering an accident claim. Over the many years in the Office Of Boating Safety I must have talked to hundreds of insurance investigators, and that was one of the many topics discussed. And if you get sued one of the first things the complainants lawyer will ask is "did you exceed the HP rating", and courts in the US accept ABYC as the standard.

All that said, in other countries they do have laws governing HP on inflatables, Canada has a standard taken directly from ABYC. The EU uses the ISO standard which was derived from ABYC, with some variations. Any country that has accepted the ISO standards also regulates HP on inflatables (that's about 70 countries)

Yes the Suzuki 9.9 and the 20 weigh about the same (I have one as a kicker on my boat) They are exactly the same engine block. But the difference is in the computer that controls it. And there are other parts on the engine that are different so you can't just change the computer.

So, exceeding the HP rating is not a good idea. Will you get caught? Probably not. But is it worth it? Probably not. There are very good engineering and safety based reasons for the HP ratings. Best to stick with them.

[DanielI]

I’m curious how these ratings apply to trolling motors. I recently bought a Sabot, which has no plate, but the formula seems to imply no motor. I was hoping to put on a small motor and use it as a tender.

Also, are the maximum weight and occupancy ratings also by formula, or based on the design?

[singlespeed]

I ran a Mariner 4 HP Two stroke for a number of years on my Sabot, as a tender while in sheltered bays. One adult and a small child are the limit, after that the freeboard is so minimum, you will attract the attention of the Harbor Patrol and will be bailing continuously.

[Ike]

A sabot is basically a sailboat and these ratings are not applied to sailboats (in the USA) If it were just a rowing dinghy then it would have to have a capacity label. Yes they use a formula but it is different than that for outboard powered boats and allows far more persons capacity as a percentage of the maximum weight capacity. Anyway, that doesn't answer your question. electric trolling motors are not considered an outboard for capacity ratings, they are considered gear weight. So even if the boat is not rated for power, you can use a trolling motor. However, the weight of the battery needs to be placed so that it doesn't put a lot of weight in the stern of these little boats. Try it and see how it affects freeboard and stability. I am familiar with what a sabot is but have no first hand experience with them. As singlespeed said it may really affect the amount of freeboard.

[tunnelvision]

Originally Posted by Nicholson58

You should sail the Caribbean. No cops, no inspections, no oversight. About 1/4 of the dinghies at night have no lights and nobody has a PFD. Most dinghies have no anchor or oars. We often see dinghies with up to 8 passengers including children and no PFD. Flairs? Hahahahahahahaha

So true and then you end up in Panama and poof tickets get written for no pfd's. The US influence is still hanging around generating revenue for the government. Thankfully the times we forgot to wear them we didn't get caught.

Originally Posted by a64pilot

My 10’6” AB is rated for a 20, as was my old Zodiac 3.10, but I can’t recommend the Zodiac.
The best prop for the AB is an 11” in SS, the Zodiac even though it was heavier was much faster and could take a 12” SS prop, the AB is much lighter, but has a much deeper V, and handles chop better, and is a drier boat, but is slower and isn’t as stable at speed as the Zodiac was.
By slower I mean 10 kts slower, the Zodiac was a 30 kt boat and stable at speed, the AB is I think in the low 20’s?
To carry 3 adults and plane with the AB requires a 10” prop, the 11 just isn’t quite up to it, but the 10” with just two people will tap the rev limiter at full throttle.

If I had 5 more HP, over the rated max, then it could get onto plane with three adults without having to slightly underprop it.

That’s one reason to have a higher HP motor.

By the way, it’s rated for 5 people or 1519 lbs, I seriously doubt it would plane with the max HP motor at half the max weight, maybe if seriously underpropped, say a 9” prop it might.

For the way we use our dinghy, I wouldn’t have use of one that won’t plane. Go to George Town in the Bahama’s, watch the people in the small dinghies coming back or going to get water or fuel, food etc, they usually arrive soaking wet, many wear foulies on just a normal day, there are many, many anchorages that you have to cross open water to get to the dock, or a snorkel site etc.

Been a few years ago but in Key West I pulled two different small sailboats off of a grounding, I had to seriously work at it too, several different pulls in different directions until I got them off, no way I could have done that with say a 9.9.

I don’t know who normally gets them off as everyone else was just passing by.

However that link I linked to on how the max HP is computed, is a CFR, which is law if your a US boat. I’m pretty certain that no one cares, but if an LEO really has it out for you, that’s another ticket they could write, I’ve never heard of it happening, but it could.

Originally Posted by Ike

A sabot is basically a sailboat and these ratings are not applied to sailboats (in the USA) If it were just a rowing dinghy then it would have to have a capacity label. Yes they use a formula but it is different than that for outboard powered boats and allows far more persons capacity as a percentage of the maximum weight capacity. Anyway, that doesn't answer your question. electric trolling motors are not considered an outboard for capacity ratings, they are considered gear weight. So even if the boat is not rated for power, you can use a trolling motor. However, the weight of the battery needs to be placed so that it doesn't put a lot of weight in the stern of these little boats. Try it and see how it affects freeboard and stability. I am familiar with what a sabot is but have no first hand experience with them. As singlespeed said it may really affect the amount of freeboard.

[ausnp84]

Interesting thread and one we’re working through at the moment.

Just bought a 2.7m inflatable with an inflatable v-floor, and the max HP rating is 6hp. There’s no mention on the plate whether it’s a 6hp two or four stroke though and looking at the outboard weights, I could probably get away with a 8/10hp two stroke for the same weight...

My question is other than flipping due to being overpowered, could the higher hp increase the speed to the point the air floor could seperate from the tubes? Or completely unfounded concern and 2-4hp won’t make that much difference?

N

[Cadence]

Originally Posted by ausnp84

Interesting thread and one we’re working through at the moment.

Just bought a 2.7m inflatable with an inflatable v-floor, and the max HP rating is 6hp. There’s no mention on the plate whether it’s a 6hp two or four stroke though and looking at the outboard weights, I could probably get away with a 8/10hp two stroke for the same weight...

My question is other than flipping due to being overpowered, could the higher hp increase the speed to the point the air floor could seperate from the tubes? Or completely unfounded concern and 2-4hp won’t make that much difference?

N

I think you are overthinking it. The boat was designed for a specific HP, why not stick with that. It's nit a rib.

[a64pilot]

If you have given up on planing, then there is no reason for a big motor, off plane a 2.5 will push you just as fast as a 6, but cost much less and weigh much less.

There are essentially two schools of thought for sailboat dinghies, a big and fast and of course expensive dinghy, a RIB, that takes up a lot of room, often requires davits to be useful
Or a small, slow and much, much less expensive often an air floor or slats etc, but not a RIB, but stows away even below.

I don’t understand why, but powerboats seem to have to have a console RIB, and a huge motor. The console kills storage space and you can’t sit forward to correct CG, so one of those fins are needed.They aren’t fast, just massively heavy.

Don’t try to make one into the other, it usually doesn’t work well.

[wingssail]

Originally Posted by a64pilot

There are essentially two schools of thought for sailboat dinghies, a big and fast and of course expensive dinghy, a RIB, that takes up a lot of room, often requires davits to be useful
Or a small, slow and much, much less expensive often an air floor or slats etc, but not a RIB, but stows away even below...

Don’t try to make one into the other, it usually doesn’t work well.

I think there is a 3rd option: a big dingy with an air inflatable floor and inflatable keel. No, it's not a rib, so it's a bit less of a "boat" in my opinion, but you can deflate it and stow it below or on deck.

My 3.6 zodiac FR with a 15hp Merc is a great dingy, light weight, reasonably fast, dry in a chop, and it is never stowed in an unseaman like manner on davits or even on deck. One big advantage is that my wife and I can easily beach it, even horse it around, and we're in our 70's. In an anchorage we can yank it up on a spin halyard in about 90 seconds, with the motor on.

The major downside is blowing it up when you get to your next port, keeping it inflated, and to a lessor extent, deflating it and rolling it into a tight bundle when you want to go to sea.

That and the fact that it is a Zodiac.

I accept those compromises to have a completely seamanlike deck for dealing with heavy weather.