Newbie Driving Question

FreeTrader · 25 March 2006, 18:14

At last the day arrived - the first opportunity to get Quick Exit in the water. I'm not an experienced rib driver, being much more used to 5 knots. So, I wondered if the gathered pro's could help me with some pointers:

Out today in fairly tricky conditions (F5-6, with very messy sea). Kind of stuff I'd cream through on a yacht, and was kind of expecting the boat (Scorp 8.5) to blast over the top of, but I was slamming, so pulled back to 25 knts, which was more comfortable. Should I have panned it and gone faster?

The bow seemed high, what should my trim settings have been? Also have bennett trim tabs, but they're not working too well, so left them alone.

Thanks in advance!

Phil

PS. None of this stopped me having a huge grin all day.

codprawn · 25 March 2006, 18:27

Yes but would you be doing 25kts in the yacht???

FreeTrader · 25 March 2006, 19:10

No dead right Codprawn - in fact 25 knots felt like warp factor 10 to me!

Rogue Wave · 25 March 2006, 19:10

Quote:

Originally Posted by FreeTrader

Out today in fairly tricky conditions (F5-6, with very messy sea). Kind of stuff I'd cream through on a yacht, and was kind of expecting the boat (Scorp 8.5) to blast over the top of, but I was slamming, so pulled back to 25 knts, which was more comfortable. Should I have panned it and gone faster?

No

Quote:

Originally Posted by FreeTrader

PS. None of this stopped me having a huge grin all day.

Good

The key to any succesful boat driving is progression. There a lot of bollox spoken about my boat does x squared Knots in a force 7 and X Cubed Knots in a force 8. At the end of the day you go out and you drive within your range of comfort and ability.....so backing off was very sensible!

goingback to progresive driving the smoother you take the waves the the faster you eventually go. if you hit them too fast then you back off/ speed up and this can be very tiring. As you get more experience of the boat then you get to go faster and learn how to fly her a bit better.

re the trim the general rule is trim down nose down. Trim up nose up your Trim tabs will make a great deal of difference to the ride particularly on an 8.5 Congratulations on buying such a good boat

Richard B · 26 March 2006, 21:09

Welcome aboard a great voyage of discovery, Phil!

Stuart has covered most of it, really.

However, what I would say is play with the boat, see what effect you get from different techniques. The Scorpion hull is great for this, very predictable and very forgiving. Once you get used to her, you'll be amazed at what you can get away with. You can go through rough water at incredible speeds, but you will need to read the waves ahead at high speed and that takes a lot of concentration. Just bear in mind that whilst the RIB is very capable, if you make a mistake at high speed, the sea might not forgive you! One of my most frequent mistakes is to accelerate too hard into waves and let the speed build up too much, but because I've driven in the way that Stu describes ("The key to any succesful boat driving is progression") I haven't got into major trouble... yet!

By October, you may find that you can blast through those waves at 40kts - the same ones that you took at 25kts today, but you will know your boat better by then and you'll know how to read the sea better by then. On the other hand, you may be out and decide that it's more sensible to take it easy... only you can decide.

Enjoy

karlT · 27 March 2006, 08:22

Hi Freetrader,

I am also a Jersey ribber and Advanced PBI. If you fancy a trip out and a few pointers give me an email lesburons@yahoo.co.uk

I skipper a 7.5 tornado for ttdivers.co.uk new boat due May/June.

i am off the rock til Easter and not back at work til May so have plenty of time.

Regards
Karl

Jimbob · 27 March 2006, 08:42

As people have said, build up you experience, as they say if in doubt dont go out.

At high speeds compared with a Yatch you need to plan you journey so that you know ehere you are, in a yatch you usually have loads of time

Simon Hawkins · 27 March 2006, 08:46

The key point to this is know your limits. Their are several threads here on how to successfully control a boat in rough conditions.

If you are heading into a head sea then you will need your engine to be trimmed in, this will lower the bow of the boat so the stem cuts throught the water. Try not to have the boat taking off too many waves as this will add additional stress to the boat, and also make the going very uncomfortable for those on board.

If you have a following sea then you will need to trim the engine out so as to raise the bow.

This is just the basic principles and their is alot more to think about, such as throttle control, angle of approach to the wave patterns.

If you are intending on going into such conditions I recommend a bespoke rough water handling course, or an advanced powerboat course.

Simon

FreeTrader · 27 March 2006, 10:42

Thanks as always for excellent advice. Went out again yesterday in F5-6, big swell, but better sea state.

This time got the trim tabs working, and the boat's performance was phenomenal. Could do 38-40 knots with total comfort and control. Amazed at the difference the tabs made.

Grin is even bigger :-))

codprawn · 27 March 2006, 13:16

Quote:

Originally Posted by FreeTrader

Thanks as always for excellent advice. Went out again yesterday in F5-6, big swell, but better sea state.

This time got the trim tabs working, and the boat's performance was phenomenal. Could do 38-40 knots with total comfort and control. Amazed at the difference the tabs made.

Grin is even bigger :-))

Thanks for that - you have just persuaded me to order the tabs for mine!!!

BogMonster · 27 March 2006, 13:49

I am probably being a thickie here but what are these "trim tabs" referred to?

sounds like a good idea, what with the Saaf Atlantic being a bit choppy...

codprawn · 27 March 2006, 14:04

Some people swear by them - others at them.

On smaller boats lots of people like the automatic types - on bigger boats you have 2 main types - normal ones - electric or hydraulic - that stick out behind the boat.

http://www.bennetttrimtabs.com/

Then there is a new type called the Volvo QL

http://www.foreandaftmarine.com/VO-QL3841717.htm

These are what I am going to fit.

Trim tabs are great for getting a boat to run level - also for correcting torque probs etc.

Alan · 27 March 2006, 15:39

You dont need trim tabs on a 5.8m RIB no matter how choppy the saarf atlantic is. Trim tabs are no substitute for a well balanced RIB and are really only needed on larger (say 7.5m upwards) RIBS and larger powerboats. The can be used to aid getting on the plane (particularly say for larger powerboats) and to counteract the 'leaning into the wind' effect that planing boats can suffer from.

For the original poster. You sound as though you know boats pretty well and of course have an excellent RIB to play in. Explore and extend your comfort zone yourself, remembering that all ribster talk in the pub about doing 40kts through Force 12 seas and pah it was nothing. Reality is often very different!
The Scorp is a capable hull and often more soft riding at 30kts than 20. Over confidence can lead to stuffing, impacted spine, ejection of passengers etc etc just as on any other RIB!

Alan · 27 March 2006, 15:39

Quote:

Originally Posted by codprawn

Some people swear by them - others at them.

On smaller boats lots of people like the automatic types - on bigger boats you have 2 main types - normal ones - electric or hydraulic - that stick out behind the boat.

http://www.bennetttrimtabs.com/

Then there is a new type called the Volvo QL

http://www.foreandaftmarine.com/VO-QL3841717.htm

These are what I am going to fit.

Trim tabs are great for getting a boat to run level - also for correcting torque probs etc.

Are these post collecting the boat from Prosport or before? If the latter then presumably this means you wont see the boat til the Autumn then?

BogMonster · 27 March 2006, 17:52

Quote:

Originally Posted by Alan

You dont need trim tabs on a 5.8m RIB no matter how choppy the saarf atlantic is. Trim tabs are no substitute for a well balanced RIB and are really only needed on larger (say 7.5m upwards) RIBS and larger powerboats.

Thanks. This is Good News as I have already spent enough on this hobby to keep my bank account looking ill for a while

codprawn · 27 March 2006, 18:14

Quote:

Originally Posted by Alan

Are these post collecting the boat from Prosport or before? If the latter then presumably this means you wont see the boat til the Autumn then?

Will fit myself - the QL ones look pretty simple.....