Drowning RIB

[Poly]

I'm surprised that people think this is scandalous neglect, and a "people shouldn't be allowed to have boats and not look after them attitude". I think its quite possible for this to happen in just a few days - especially if the transom is low/cut down.

Many people will leave there boats afloat and not be able to visit them for a couple of weeks, if a battery dies or a pump/float switch fails then problems quickly escalate. If circumstances conspire against you and it turns out you don't get down to your boat for a month - then shit happens - and your glad you bought a RIB so its still afloat, and hopefully glad the boat was well rigged with electrics and fuel breather etc. out of the water.

I know of one sailing club where the boats are normally used twice a week and its still not uncommon for their rib to be very full of water in bad weather.

[Nos4r2]

Originally Posted by Chris

I'll wake up to find myself gaffa taped to a console with 3 feet of Homebase drain pipe up my arse.

Takes me back to school days hey gotchiguy?

I knew they were a bit odd near Stroud...

[9D280]

I'll second the "doesn't take long" thing. Once worked at a place with a fleet of moored wayfarers. One night of heavy rain & most wre up to the top of the bouyancy tanks. On the plus side to this, it shows you how reliable a swamped rib is at staying afloat!


As for the mooring thing, Pol is spot on with the damped load, however you also have to remember that the swamped boat is still only displacing the amount of water the hull / toobs can displace. the water inside is part of the medium it's floating in (as I assume there is a free flow iof water over the transom by this point).

Yes, if you tried to tow it, you'd feel the full effect of the ton or so of water, as you are trying to shift the whole lot. But when moored, I'm with Polwart on the windage theory.

[PeterM]

Originally Posted by Polwart

I'm surprised that people think this is scandalous neglect, and a "people shouldn't be allowed to have boats and not look after them attitude". I think its quite possible for this to happen in just a few days - especially if the transom is low/cut down.

Surely if you know your boat has a low transom etc you would take more care / check more often , or pay someone to if you knew bad weather was on the way?

Just seems a huge shame.

As an aside I'd go with the view of the mooring being under alot more stress. Windage is bugger all either way as its a swinging mooring by the look of it - but it will have a few tons of water to restrain. Yes it will move less , but looking at the momentum you have to restrain in the extra mass. I dont think you can consider it as a free moving mass of water inside the boat . If that was the case the flooding hull on Seariders wouldn't work !

[9D280]

But that's WHY they work - boat sits low in the water with less windage & more momentum, so moves a lot less.

Accelerate hard & the laws of physics say that the water wants to stay put and becasue it's not entirely restrained (the big hole) kinetics forces it out the back.


Could the ratings on a mooring be the breaking strain of the chain?

[Channel Ribs]

Originally Posted by 9D280

But that's WHY they work - boat sits low in the water with less windage & more momentum, so moves a lot less.

Accelerate hard & the laws of physics say that the water wants to stay put and becasue it's not entirely restrained (the big hole) kinetics forces it out the back.

If you are right then it is possible to accelerate gently in a Searider and keep all the water in the hull.

Surely it is good old gravity that drains the hull? As the boat rises, nose first, from the water.

[Searider]

Originally Posted by 9D280

Could the ratings on a mooring be the breaking strain of the chain?

Mooring chain is normally sized to last a couple of years and still be strong enough to be able to lift the sinker. The boat bobbing around on the top is usually the least of its problems.

[Poly]

Originally Posted by Blackroady

Surely if you know your boat has a low transom etc you would take more care / check more often , or pay someone to if you knew bad weather was on the way?

Just seems a huge shame.

Maybe, but maybe the owner knows that his electrics are all OK, and his fuel tank is either not on board or well above the flooded waterline - in which case apart from having to bail like mad he's not really any worse off is he? and probably less likely to get nicked too!

[alystra]

The passing of an average Spring/Summer depression in these parts (3/4 days-ish) would often fill Moon Raker to transom level, with no chance of me being able to row out to her because of the wind. She could be sitting there full of water for a week. She was much more stable in the wind and waves. She wasn't being neglected though - I can see her from most of the windows in my house. Two reasons made me fit another pump with a float switch.

First, I got fed up of getting aboard into a swimming pool. Second, when laid up last year, I opened up the drain hole from the hull to find water inside. I reckon this was getting in via the console and seat holding down bolts. A foot or so of water head may have forced water past any sealant. It's probably adequate for a wet deck and the odd slosh of water.

I shall check on the next fine day.

[9D280]

Originally Posted by malthouse

If you are right then it is possible to accelerate gently in a Searider and keep all the water in the hull.

Well, I don't know about you, but I certainly have never managed to empty a searider at tickover....... Remember at sub planing speeds, the water pressure at the exit hole will be more than enough to counteract the momentum.

Problem is you need to get on the plane, and to do that you have to force some of your ballast out the back against the water pressure. Granted if you got 60 on the back of your SR4 this discussion is slightly irrelevant, as it will plane regardless, but for a laugh try it on one with the minimum rated HP on the back!

Originally Posted by malthouse

Surely it is good old gravity that drains the hull? As the boat rises, nose first, from the water.

Aye, and once the nose is in the air the stern is forced down, so the back pressure on the exit hole is higher...... Once you're PROPERLY on the plane gravity is in full effect, but you need to get up there first - I assume you've not seen / experienced the "permanent nose in the air" trick at mid throttle or with a smaller engine?

[Channel Ribs]

Originally Posted by 9D280

I assume you've not seen / experienced the "permanent nose in the air" trick...

You assume wrongly sir! I am a master of the permanent nose in the air, not just with Seariders neither.

With just the right trim/rev combo it is quite possible to remain oblivious to all that lies ahead for quite some time.

[SPR]

Yes - SR4 with 25HP Four Stroke on back was interesting, crew had to go to front to get it on plane...

I was once told by Zodiac - that if you kept you boat on a mooring to leave self bailers open, the theory that the water preasure would will equalise....i tried that, but ended up fitting auto pump! Was fed up with wet feet.

S.

[m chappelow]

Originally Posted by SPR

Yes - SR4 with 25HP Four Stroke on back was interesting, crew had to go to front to get it on plane...

I was once told by Zodiac - that if you kept you boat on a mooring to leave self bailers open, the theory that the water preasure would will equalise....i tried that, but ended up fitting auto pump! Was fed up with wet feet.

S.

i have heard that too ,,,though i think it only works if the boat has its engine removed and there is no other weight in it ,

[Maximus]

Originally Posted by Chris

I'll wake up to find myself gaffa taped to a console with 3 feet of Homebase drain pipe up my arse.

Takes me back to school days hey gotchiguy?

You still having Those dreams Chris!!? I know Matt's got over the Feather poisoning episode [Biting all those pillows!] from his time at Public school,hoped you'd moved on too!

[JSP]

Originally Posted by Maximus

You still having Those dreams Chris!!? I know Matt's got over the Feather poisoning episode [Biting all those pillows!] from his time at Public school,hoped you'd moved on too!

[MIRO Stewart]

Originally Posted by SPR

Yes - SR4 with 25HP Four Stroke on back was interesting, crew had to go to front to get it on plane...

I was once told by Zodiac - that if you kept you boat on a mooring to leave self bailers open, the theory that the water preasure would will equalise....i tried that, but ended up fitting auto pump! Was fed up with wet feet.

S.

I would agree with the above and with what polwart said before re neglect. It does not look to me like the boat is being neglected. He has trimmed the engine right up out of the water thus preventing it getting flooded.

My rib has an extremely low transom and doesnt take much for it to fill up. I also keep in on a pontoon in the summer so when there is particulalry bad weather forecast, we droppe the self bailers and let it "sink". Its going end up sunk overnight anyway and by sinkking it first it stops it getting tossed around as much.

As someone said earlier, the guy is lucky its a rib and I'm guessing probably has his electrics/fuel set up so it can sink. I sunk my rib this summer whilts switching fuel tanks. I took a couple of waves over the stern and that was me done for. I hadnt trimmed the engine up first so it got flooded but since its a rib, i didnt have to take a swim. Fortunately, I was out with 3 other ribs so they towed me in.

Dont be too quick to jump to conclusions about peoples boats, you dont know their circumstances or how the boat is set up. It really doesnt take long for them to sink and once they are full of water, they are full of water, nothing else can happen!

[GordyP]

A perfect example of the benefits of an open transom - everyone should have one, works really well when you rip the tubes off too .