Sinkin Feeling

[Tiffy]

We have a New 6.3 meter Humber Rib with a 80 HP Long Shaft Yamaha.

When anchored water slops over the stern and fills the Rib. We feel there
is not enough buoyancy in the hull , or rear tube protrusion lift.

Has anybody else had this problem with Humber or any other makes.

Is there any solution to this problem ?

[Nos4r2]

I think saw that at Calshot a few weeks back?


Do you have a lot of water in the hull? Is it coming over the transom when she's head to wind at anchor?

[Matt-V-SAR]

I think saw that at Calshot a few weeks back?


Do you have a lot of water in the hull? Is it coming over the transom when she's head to wind at anchor?

Hiya,

The stern does not seem to have much lift to it. As Tiffy said protrusion of the rear Sponsons dosnt seem as good as on the new 4 meter humber Venturer Three that just entered servcie.

and yes, water Is coming in over the transom
Photos Below, 1) Humber 6.3 Ocean Pro, 2 + 3 New Venturer Three, Tubes seem to extend further compared to the larger RIB?

[Tiffy]

Below deck is dry . Water slops over the transom which is only a few inches
below water level when at anchor. Does not come over the bow ; but as
it pitches the stern goes below sea level. We also only have a 80HP engine
and the design is supposed to take much large and heavier engines.
Talking to Humber today , they suggested we should have fitted
a extra long shaft giving 5 more inches transom height . I am surprised
they did not mention this when we special ordered the Rib , if they know it
can be a problem.That perhaps all their larger Ribs should be supplied
with a extra long shaft transom . We also had a problem with the
under fuel fuel tank. The main depth was to the stern , and the filler
cap in the bow. Afloat you could not fill it full . and on the trailer
at a tilt and you then opened the front filler cap all the fuel shot out in
you face. We rectified this problem by turning the fuel tank gauge tube
into the filler , and reverting to eyeball calibrated dip stick. They also
suggested we fit a electric bilge pump with a second battery . Although
with the amount of water it takes this battery would not last long.
I noted at the Southampton Boat Show , many Ribs had self bailing
shields on the stern . Which is the way we might have to go at our cost.
Thanks for getting in touch ; and I would be interested in any other
makes of Ribs have this problem . Although they may never sit at
anchor most of the day.

[Dirk Diggler]

An XL would put the prop 5'' deeper in the water, it wouldn't raise the motor on the transom.

[Bigmuz7]

I had a 5.8 hull with this problem (Northcraft), at anchor wasnt so bad when it went nose to wind,but some water still spilled in,.. but drifting could not be done, as too much entered over the dropped area where the motor was mounted. The motor was the max HP for that hull, although it was a 2 stroke, the sponsons were not big/long enough to give enough flotation, and also, I only had a single Jockey lineup in the middle of the boat, so there wasnt enough bow weight, to balance the load on the transom. In the end the transom was raised and the motor with it by a couple of inches IIRC to cure the problem, it was easily achieved and there was enough space on the motor mounting plate to raise it, also, the installer had set it too deep to start with which meant no real loss in performance was noted after the mod was done

[Pete7]

Originally Posted by Dirk Diggler

An XL would put the prop 5'' deeper in the water, it wouldn't raise the motor on the transom.

Rubbish, you know what he meant

Tiffy, did you buy the hull and engine separately by chance? Why didn't you tell them what it was to be used for or even ask for advice here on Ribnet. You only had to put a post up asking for advice, its free and you get really good advice from folk that don't have a financial interest in flogging you something.

You asked which other ribs do it, one is the Deltas but they have a GRP and hyperlon skirt inside the transom to keep the slop out of the boat.

Pete

[J S]

Originally Posted by Dirk Diggler

An XL would put the prop 5'' deeper in the water, it wouldn't raise the motor on the transom.

I thought the transom was built up higher also on humbers so you can have a high transom but have to fit an XL Engine.?

James

[Ian Sharlot]

Originally Posted by Dirk Diggler

An XL would put the prop 5'' deeper in the water, it wouldn't raise the motor on the transom.

I think you may have your fact wrong there, An XL will lift your engine 5" and would of cured the problem.

[codprawn]

Originally Posted by Ian Sharlot

I think you may have your fact wrong there, An XL will lift your engine 5" and would of cured the problem.

How? The only thing that will stop water coming in is to have the top of the transom itself higher out of the water!!!

[Pete7]

Originally Posted by codprawn

How? The only thing that will stop water coming in is to have the top of the transom itself higher out of the water!!!

Doh, which would be achieved with an XL engine and a bit of 4 x 2"

Pete

[Ian Sharlot]

Originally Posted by Tiffy

We have a New 6.3 meter Humber Rib with a 80 HP Long Shaft Yamaha.

When anchored water slops over the stern and fills the Rib. We feel there
is not enough buoyancy in the hull , or rear tube protrusion lift.

Has anybody else had this problem with Humber or any other makes.

Is there any solution to this problem ?

Is it possible to fit a couple of pieces of stainless plate on each side of the engine to fill the gap where the water is coming over?

[Stoo]

Originally Posted by Tiffy

Water slops over the transom which is only a few inches below water level when at anchor.

Yowsers... You're transom is actually UNDER the water, at rest??? Is this a new boat? Has it always done this? If so, I think I would be raising H*ll with the dealer and manufacturer. The whole "point" of a boat, is to form a hole in the water where you keep your stuff...

The transom on my Hurricane is only about 4" above water at rest, but it's very buoyant and water never comes over (even with my shiny new 4-stroke) it unless I am backing up into a sea. There is also a bit of decking right there which covers a wet-bilge. The area on top of this decking is self draining.

Seriously though, this is a completely unacceptable situation and the manufacturer and dealer must figure out why it's happening. Failing that, I'd be placing a call to my lawyer...

[Stoo]

Originally Posted by Ian Sharlot

Is it possible to fit a couple of pieces of stainless plate on each side of the engine to fill the gap where the water is coming over?

Undoubtedly, this could be done, but he shouldn't have to do anything! His nice new boat is sinking... If it wasn't a RIB, it would sink at the mooring... literally!

As I typed this, I recall a friend who had a small rib years ago... 4m or so. The dealer supplied a regular shaft engine by mistake, where a long shaft was required. Of course it cavitated like crazy, so the dealer's solution was to cut the transom down by several inches, leaving only an inch or two of freeboard. Even at that, water still didn't come in over the top, unless he reversed, but the scuppers and bilge bump could manage that.

Is there any chance that something like this could have happened?

[BruceB]

The higher transom using an XL engine means the prop is at the same place as normal length shafts but the power head is 5" higher. The whole transom is 5" higher out the water to take account of this.
I am surprised that the transom is slopping water over at anchor, to be expected to some extent when reversing but not stationary.
I ordered the XL transom on mine having used the same hull with the standard and it is now very dry but obviously its a bit late for that solution for you now.
This is a pic of our boat with the XL transom, as you can see there is a fair amount of freeboard and the motor is a very heavy Suzuki at 185kgs so its no lightweight hanging off the stern. The motor notch if it was 5" lower would be very close to the water so I reckon even long shafts are too short for comfort on these hulls
What are Humber saying about it?

[The Grocer]

Any chance of a photo of this boat at rest? Our 6.3 OP has a 150 Suzi XL -about 220Kg- on the back, and the only water we've had to pump out has been rain (not that we get a lot of that up here... ) Then again, Cowal has 2x forward mounted 72L tanks and a 6 man liferaft at the pointy end, as well as the higher transom (but the notch for the engine is, I think, at roughly the same height as a standard transom - the higher parts are really only to deflect following seas. [An expert will be along shortly to correct this ]).

And are you really, totally, absolutely sure there's no extraneous liquid inside the hull? "Mingulay" comes to mind...

[Cookee]

If it's under warranty take it back!

[Tiffy]

We are going to fit a Yamaha 115 with a extra long shaft , and BHG
our local Avon and Yamaha Dealer is going to raise the transom . Hope Will
be back on service 27th September. In reply to another Posting the
Rib was specially built by Humber who knew we were going to use
it as a Training and Rescue Rib. They also knew we were going to
fit a 80 HP Yamaha 4 stroke , which is less that the maximum rated
HP. Rather surprised at this late date Humber have suggested a
extra Long Shaft . What I am wondering does only Humber's suffer
from this problem , and why do some Ribs not suffer from water
slopping over the transom .Do they have larger tubes and greater rear protusion
and more buoyancy in their hulls ?

I am rather to the conclusion from a safety point of view all
Ribs with the larger heavier 4 stroke engines should have self bailing
wells . Some of which I saw at the Southampton Boat Show.

[PeterM]

Its all down to design - check out the transom on the RNLI boats. They dont have one , but do have water running in , but are designed that way. Its very odd that your is so low, is there anything else that pulls the back down ? Your tubes must be virtually under water at the stern which is just not right. To pull that much bouyancy down must take a huge weight of something !

[captnjack]

Originally Posted by Blackroady

Its all down to design - check out the transom on the RNLI boats. They dont have one , but do have water running in , but are designed that way. Its very odd that your is so low, is there anything else that pulls the back down ? Your tubes must be virtually under water at the stern which is just not right. To pull that much bouyancy down must take a huge weight of something !

I'm thinking the same thing. "Something is very wrong with this picture."

Honestly, before spending money I would take a picture of the boat from the rear while its in the water. Post it here so we can see what's going on and maybe offer more tailored help resolving it.