Playing around the Clyde

Jampot · 26 February 2018, 11:51

https://photos.app.goo.gl/sSAJvFP4XsHTWdYl1

Early start on Sunday morning forced by high tide at 0630 and very shallow approach to Dumbarton harbour.

Weather forecast was for South/South Easterly at circa 15-20 mph winds. This was upgraded by Belfast Coastguard to Force 5 occassional 6 in the afternoon, only really noticed the roughness on exit of Loch Fyne and particularly between Gourock and Langbank on the home straight.

Tracey and I are building up for a summer on the west cost including a planned trip to St Kilda, so spending time getting to know our boat and our/its limitations.
In choppy water the Pascoe SR7 performs really well, at 35 knots it simply skims over the top of the waves and the ride remains very comfortable.

Fuel economy on our new Mercury Verado 200HP is fantastic. We averaged 1.2 litre per mile at 35 knots and were doing an average of 27 litres per hour for most of the day.

At 4500 RPM we were gtting 49 knots. Very enjoyable and still 1500 RPM's to go

aRIBaderci has a 220ltr tank, and the foredeck easily accommodates another 100ltrs. We've sourced a 30hp 2 stroke aux and are building up our supply of other items for the boat (some camping gear, bivvy bags, stove, PLBs, spare VHF and spare mobile phone).

Next burst of good weather we plan to head to Sanda island off the Mull and maybe sneek a look of Rathlin Island.http://www.rib.net/forum/images/smilies/whistling.gif

After all the hassles at the start we are absolutely loving our rib.

Xk59D · 26 February 2018, 12:00

49 knots from a 200 and only 4500rpm? is that even possible mathematically???

I only get 47 knots flat out at more or less 6k with my 200 on a 6.8 and that is trimmed well out and light. More realistically it is about 44knts. I know ribcraft are very heavy with no planning pad but I didn't think it was THAT much different.

If the speed is from the peto that would explain it as they are wildly innacurate.

Jampot · 26 February 2018, 12:12

Quote:

Originally Posted by Xk59D

49 knots from a 200 and only 4500rpm? is that even possible mathematically???

I only get 47 knots flat out at more or less 6k with my 200 on a 6.8 and that is trimmed well out and light. More realistically it is about 44knts. I know ribcraft are very heavy with no planning pad but I didn't think it was THAT much different.

If the speed is from the peto that would explain it as they are wildly innacurate.

The engine is not the biggest factor it is the hull. The PASCOE has a twin stepped kevlar hull, it was designed by the Swedish Racing Team Ocke Mannerfelt. It flies. Your Ribcraft is much heavier and sits in the water, the Pascoe sits above it.

Xk59D · 26 February 2018, 12:16

I know what a Pascoe is but I didn't think it was a 60knot ish boat with a 200 on it, everyday is a school day.

jonp · 26 February 2018, 12:21

What pitch prop, would be interesting to see on a prop calculator how much slip you are getting at 4500rpm and 49 knots.

Jampot · 26 February 2018, 12:22

Quote:

Originally Posted by Xk59D

I know what a Pascoe is but I didn't think it was a 60knot ish boat with a 200 on it, everyday is a school day.

Sorry didn't mean to leave pascoe in capitals. Hope to see you round the Clyde some time. Cheers

Jampot · 26 February 2018, 12:47

Quote:

Originally Posted by jonp

What pitch prop, would be interesting to see on a prop calculator how much slip you are getting at 4500rpm and 49 knots.

Stainless steel Mercury 3 Cleaver - I think 15 x 22 rotation.
Would slip some on racing start but top end speed is better.
also Mercury autotrim which is excllent for both perfomrance and economy
With the upgrade I've noticed no meaningful gap in peformance v the Optimax 225.

Andy_Rs600 · 26 February 2018, 13:20

Having driven one of these with a 150 optimax and been genuinely surprised at the top end I'd certainly believe the number being quoted.

Xk59D · 26 February 2018, 13:40

If it is a 6 cylinder model then it is damn close to 0% slip, can't ask for more than that. Cracking setup

gtflash · 26 February 2018, 14:37

They are the same hull as a backdraft or a b23 I believe which both great racing hulls. Amazing stability and fly extremely level. Better into the wind than downwind where the race boats could stuff. Looks good too.

I looked at a 225 that was running over 55 knots and a 250ho that run 70mph. My scorpion stepped hull in light build ran 71mph with more rpm and that’s a bigger boat.

Less weight more speed. Simples

willk · 26 February 2018, 15:20

Quote:

Originally Posted by Xk59D

I know what a Pascoe is but I didn't think it was a 60knot ish boat with a 200 on it, everyday is a school day.

The figures seem ballpark right to me. Those things are rocket ships, apparently they actually "sit above the water" while you have to shoulder tons of the stuff aside when cruising in the Vital Spark.

I bet 44kts is ruined for you now...

Xk59D · 26 February 2018, 16:42

I never sit at 44 knots so not ruined, it spends its life at 22 knots or so as it is best fuel about there.