No kill cord in Florida = Missile!

[Iankristy]

Originally Posted by Daibheid

Hooking is not the exclusive preserve of trainees - by a long way! On that occasion I was Training Officer for a dive club and training a few coxw'ns. They have to get experience at all speeds and that trip was me, a trainee diver and a trainee cox with quite a few hours up. We were on a long transit to collect divers on an empty 4.5m 50HP RIB with tiller steering. I'd taken the boat out to sea and clear of the nasty stuff and handed over to drive a straight line to a mark 5nm away. I'd cautioned that the tiller needed a firm hand and if it got away at all, it'd end badly and to take it easy and get a feel before using big throttle openings.

All was well for five minutes, 1m open ocean swell on a sunny smooth sea. But rather than sit on the tubes as normal, I chose to sit across the deck, back and feet wedged between the tubes. Just in case.
I noticed our heading swing a few degrees a few times and called it out. Perfectly normal instructing anyone driving fast boats. We eventually seemed to settle in to a straight course and inevitably the throttle got wrung open while holding a straight course. Ideal conditions and part of learning but sooner than I wanted and said so. Seconds later I thought we were starting to veer slightly again to port so turned and said "watch it". I saw the port side trainee leaning into the RIB at which point g-force was kicking in and he'd no leverage except his bootees on a wet deck and I could see it coming. It was over in a millisecond.
At full thrust, he let the tiller get that fraction too much off centre, overpower him and break free. At about 25-30 knots, the engine snapped hard to starboard, the RIB turned instantly and violently 90deg to port. The forward momentum made it continue on the original line of travel - now sideways - and it promptly used the starboard side of the V hull as a ramp and launched itself into a sideways jump.
The keel and chines stopped it -like it hit a wall. The cox went up and flew across the boat and slammed into the diver sitting opposite on the starboard quarter. Adrenaline had them locked on to the small A-frame and incredibly they withstood the G force from being ejected along with the Cox cannoning across! The RIB almost flipped over sideways but settled for violently rocking
There was spray everywhere, the engine screaming on the rev-limiter and cavitating and two white as a sheet faces tangled together. I was certain there had be a fractured skull -or worse- and the blood was about to come. I killed the engine and keyed the radio about to call a Mayday but realized no-one appeared to have been hurt. It was a very scary experience all round especially as back in the early Nineties kill-cords were rare.
Near perfect conditions but big tiller outboards need attention especially on a boat with a lot of keel.
I put the utterly terrified and distraught trainee cox back on the helm and we continued at a more subdued pace.
Several lessons learned.

Sounds pretty bad. I rest my case!

[Daibheid]

Originally Posted by Matt

I've experienced the same - didn't hook it, but they really can bite can't they.
Can you get dampers for them?

My ZapCat has a tiller extension combined with a damper that also restricts the Tohatsu50 from maximum lock. It's a class racing mod requirement and really makes it a doddle to drive.
I've seen different designs on big outboards, some using bike steering dampers, but most seem custom fabricated.
Leverage is probably the priority to improve control on bigger outboards.

[Daibheid]

Originally Posted by Iankristy

Sounds pretty bad. I rest my case!

If "your case" continues to be ensuring trainees shouldn't get close to hooking then I'm not sure you realise how easy it can be for anyone to hook a RIB in even benign conditions. There are a lot of variables at play, especially different boats' characteristics so experience of many different boats broadens appreciation of the risk.
Just my $0.02 worth but a hook happens when turning with high G - slow speed hard turn or a gentle arc at high speed - and lateral grip is suddenly overcome. The hull skips upward sideways using the outward hull flank as a ramp with momentum and prop thrust for power. Then the keel starts to grip again. Sometimes in a gradual skipping as momentum dissipates, other times with a bang.
My experience is the Mediterranean styles with shallow V hulls made to go fast with smaller engines will hook but tend to skid rather than hook violently. So you can crank them hard over at speed and they'll drift rather than hook. Usually the inside tube will be hard into the water carrying a lot of weight and keeping the outside flank of the hull at a safe angle to the water. Hence the slide until the helm comes back in line or the boat slows right down with the prop aerated.
Deeper V hulls and/or tubes that ride well clear of the water when planing will grip much harder and so generate higher G force. But when lateral grip is exceeded they tend to grip hard on the first sideways jump. Cue injuries and ejections.
So is your case restrict trainees from hard/fast high G turns?
Of course that's an option - if you're going to provide a restricted certification.
But it doesn't eliminate the risk of a hook, especially in the deep V and/ or deep- chined boats. Why? Because you can be turning safely with a big safety margin and cross an unseen piece of chop or wake at just the right angle to significantly reduce the amount of keel in the water and exceed lateral grip and suddenly hook.
If you're at sea in choppy conditions the risk is increased when turning up into chop but manageable by adjusting the rate of turn when near beam-on. Of course you train for it but experience of fast and hard turning in a RIB is essential for RIB trainees along with clear instructions on the hook hazards and minimisation thereof. At least on my watch.

[Limecc]

With hooking does it only apply to tiller steer?

[Matt]

Absolutely not.
The mannefelt B23 race boats race in class 3 in the UK were notorious for being exceptionally fast, but would bite you hard if cornered incorrectly, irrespective of the conditions.

Lots of rigs can be made to hook. It’s just the tiller setup on big outboards that we covered here

[Iankristy]

[QUOTE=Daibheid;832791]If "your case" continues to be ensuring trainees shouldn't get close to hooking then I'm not sure you realise how easy it can be for anyone to hook a RIB in even benign conditions. There are a lot of variables at play, especially different boats' characteristics so experience of many different boats broadens appreciation of the risk.

Just my $0.02 worth but a hook happens when turning with high G - slow speed hard turn or a gentle arc at high speed - and lateral grip is suddenly overcome. The hull skips upward sideways using the outward hull flank as a ramp with momentum and prop thrust for power. Then the keel starts to grip again. Sometimes in a gradual skipping as momentum dissipates, other times with a bang.

My experience is the Mediterranean styles with shallow V hulls made to go fast with smaller engines will hook but tend to skid rather than hook violently. So you can crank them hard over at speed and they'll drift rather than hook. Usually the inside tube will be hard into the water carrying a lot of weight and keeping the outside flank of the hull at a safe angle to the water. Hence the slide until the helm comes back in line or the boat slows right down with the prop aerated.

Deeper V hulls and/or tubes that ride well clear of the water when planing will grip much harder and so generate higher G force. But when lateral grip is exceeded they tend to grip hard on the first sideways jump. Cue injuries and ejections.

So is your case restrict trainees from hard/fast high G turns?

Of course that's an option - if you're going to provide a restricted certification.

But it doesn't eliminate the risk of a hook, especially in the deep V and/ or deep- chined boats. Why? Because you can be turning safely with a big safety margin and cross an unseen piece of chop or wake at just the right angle to significantly reduce the amount of keel in the water and exceed lateral grip and suddenly hook.

If you're at sea in choppy conditions the risk is increased when turning up into chop but manageable by adjusting the rate of turn when near beam-on. Of course you train for it but experience of fast and hard turning in a RIB is essential for RIB trainees along with clear instructions on the hook hazards and minimisation thereof. At least on my watch.

Yep get all that. Perfectly aware thanks. Doing 500 hours a year on rib with passengers on board it comes in handy. That’s why all this is taught at lower speeds and trainees comprehend they need to get the keel in the water. They’re also sat next to an instructor who’s next to the throttle. Any instructor who’s getting hooked out his boat needs to have a wee think