Go Back   RIBnet Forums > RIB talk > RIBs & ribbing
Click Here to Login

Reply
 
Thread Tools Search this Thread
 
Old 03 October 2013, 14:24   #1
Member
 
Country: Ireland
Town: Castlebar
Boat name: Clewless
Make: Valiant DR 490
Length: 4m +
Engine: 60 hp ETEC
MMSI: Awaitng one
Join Date: Oct 2007
Posts: 1,339
RIBase
Riding on the back of a wave in a following sea

Has anyone ever noticed that when riding on the back of a wave in a following sea, that the power sometimes seems to get robbed from the engine and the engine will sometime appear to labour?

I assume that this is due to the circulr motion that a water particle has within a wave and this motion is trying to pull the boat down the back of athe wave.

TSM
__________________
two stroke mick is offline   Reply With Quote
Old 03 October 2013, 14:42   #2
Member
 
The Black Pig's Avatar
 
Country: UK - England
Town: Salcombe
Boat name: The Black Pig
Make: Ranieri
Length: 4m +
Engine: 60c hp tohatsu
MMSI: 235038018
Join Date: Jun 2013
Posts: 443
Send a message via AIM to The Black Pig
Yes I have have noticed this too, first time it was quite alarming as I was in big seas over a bar, thought I had lost the prop or sumitt
__________________
The Black Pig is offline   Reply With Quote
Old 03 October 2013, 14:57   #3
Member
 
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
It's just the fact your trying to drive the boat up a big hill.... usually water is flat!
__________________
PeterM is offline   Reply With Quote
Old 03 October 2013, 15:11   #4
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 12,178
RIBase
Quote:
Originally Posted by two stroke mick View Post
Has anyone ever noticed that when riding on the back of a wave in a following sea, that the power sometimes seems to get robbed from the engine and the engine will sometime appear to labour?

I assume that this is due to the circulr motion that a water particle has within a wave and this motion is trying to pull the boat down the back of athe wave.

TSM
I remember one particular incident coming out of Milford Haven round St Annes head, we had a 6.4m Osprey at the time with a 175hp inboard. As we rounded the head we hit a patch of standing waves & got half way up the back of one & then started to slide backwards 4rse first into the trough & this was at WOT The boat was near vertical & I thought she was going over backwards, luckily we managed to crest the wave & escape, scary
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:Don't feed the troll
Pikey Dave is offline   Reply With Quote
Old 03 October 2013, 15:40   #5
Administrator
 
John Kennett's Avatar
 
Country: UK - England
Town: Brighton
Length: 3m +
Join Date: May 2000
Posts: 7,109
Horsepower doesn't count for much when you're pointing into the sky, and as it's slow going in these conditions you're effectively trying to do a standing start up a very steep hill.

The "Isle of Man" trip a few years ago saw us in some interesting conditions off Anglesey, stern sliding a big Ribcraft with 250 screaming horsepower doing nothing at all. Poly seemed to take it in his stride, but the rest of my crew have never set foot in a boat again!
__________________
John Kennett is offline   Reply With Quote
Old 03 October 2013, 15:43   #6
Member
 
Adamn's Avatar
 
Country: UK - England
Town: Helston
Boat name: Myrtle
Make: Zodiac pro 500
Length: 4m +
Engine: Outboard 60hp
Join Date: Sep 2012
Posts: 259
Not nice looking at the sky in a NASA launch position!!
This happened to me going to the Scillies with Whisper and company on the Runnel Stone just off Lands end.
Not much fun in a small Rib.
__________________
Adamn is offline   Reply With Quote
Old 03 October 2013, 16:05   #7
Member
 
Country: UK - England
Town: Bristol
Make: Ribcraft
Length: 5m +
Engine: Yamaha
Join Date: May 2006
Posts: 4,299
Not much fun in a small rib!! Awesome fun in a small rib
__________________
matt h is offline   Reply With Quote
Old 03 October 2013, 16:18   #8
Member
 
Adamn's Avatar
 
Country: UK - England
Town: Helston
Boat name: Myrtle
Make: Zodiac pro 500
Length: 4m +
Engine: Outboard 60hp
Join Date: Sep 2012
Posts: 259
Quote:
Originally Posted by matt h View Post
Not much fun in a small rib!! Awesome fun in a small rib
Not when you really really think you are going over! It stayed vertical for several seconds before dropping back down. The rubber seal on the engine cover actually got turned up at the back.
__________________
Adamn is offline   Reply With Quote
Old 03 October 2013, 16:35   #9
Member
 
Maximus's Avatar
 
Country: UK - England
Town: Wild West
Boat name: No Boat
Make: No Boat
Length: under 3m
Join Date: Jan 2008
Posts: 5,306
Send a message via AIM to Maximus
Quote:
Originally Posted by matt h View Post
Not much fun in a small rib!! Awesome fun in a small rib
Yeah till YOU Stuff it!!! eh Matt!
__________________
A clever Man learns by his mistakes..
A Wise Man learns by other people's!

The Road to HELL ..is Paved with "Good inventions!"
Maximus is offline   Reply With Quote
Old 03 October 2013, 16:37   #10
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
Quote:
Originally Posted by matt h View Post
Not much fun in a small rib!! Awesome fun in a small rib
Yeah but your nuts
__________________
Member of S.A.B.S. (Lancashire Division)
kerny is offline   Reply With Quote
Old 03 October 2013, 16:45   #11
Member
 
Country: Ireland
Town: Castlebar
Boat name: Clewless
Make: Valiant DR 490
Length: 4m +
Engine: 60 hp ETEC
MMSI: Awaitng one
Join Date: Oct 2007
Posts: 1,339
RIBase
I be with MattH on this one. I also think it is good fun but requires a lot of wok to keep the boat on the back of the wave
__________________
two stroke mick is offline   Reply With Quote
Old 03 October 2013, 17:37   #12
Member
 
Exe treme's Avatar
 
Country: UK - England
Town: Exeter
Make: Highfield
Length: 5m +
Engine: Honda BF90
Join Date: Mar 2013
Posts: 272
Quote:
Originally Posted by PeterM View Post
It's just the fact your trying to drive the boat up a big hill.... usually water is flat!
Yep, like uphill pedalling on a bike. The hull wants to slide back down the wave.
__________________
Happy when wet!
Exe treme is offline   Reply With Quote
Old 03 October 2013, 19:39   #13
Member
 
Boatnomad's Avatar
 
Country: Ireland
Make: Zodiac Mk I
Length: 3m +
Engine: 15 hp Yam two stroke
Join Date: Feb 2012
Posts: 728
Yep, deceptively fast moving water.........
Attached Thumbnails
Click image for larger version

Name:	##-.jpg
Views:	211
Size:	120.0 KB
ID:	86034  
__________________
Boatnomad is offline   Reply With Quote
Old 03 October 2013, 19:43   #14
Member
 
JamesF's Avatar
 
Country: UK - England
Town: Sidmouth
Boat name: Various
Make: Avon, Ribcraft
Length: 4m +
Engine: Mercury 40, Honda 50
Join Date: Nov 2012
Posts: 266
I've had a similar problem — following a wave in at about half throttle, off the plane so going too slowly to land, opened up to WOT and got no response at all.

The much finer prop that'd been on there previously was much better for climbing waves (but a bit too much of a compromise for everything else). The technique for approaching the beach has needed a bit of a re-think since then...

Also, water runs downhill — so rather than being exactly like driving uphill, it might be like walking up the wrong side of an escalator. (Third hand wisdom of my brother's old dinghy sailing coaches there — I'd be interested to see any figures on whether it's true and to what extent.)
__________________
JamesF is offline   Reply With Quote
Old 03 October 2013, 19:57   #15
Member
 
martini's Avatar
 
Country: UK - Channel Islands
Town: jersey
Boat name: Martini II
Make: Arctic 28/FC470
Length: 8m +
Engine: twin 225Opti/50hp 2t
MMSI: 235067688
Join Date: Jun 2005
Posts: 3,030
Still just about the safest place to be in a big following sea
__________________
martini is offline   Reply With Quote
Old 03 October 2013, 21:32   #16
Member
 
tony t's Avatar
 
Country: UK - Wales
Town: west mids /tywyn
Boat name: HAWK
Make: RIBCRAFT/ Suzuki 250
Length: 7m +
Engine: Tohatsu 3.8/15hpsuzi
MMSI: 235086594
Join Date: Apr 2008
Posts: 4,270
Quote:
Originally Posted by John Kennett View Post
Horsepower doesn't count for much when you're pointing into the sky, and as it's slow going in these conditions you're effectively trying to do a standing start up a very steep hill. The "Isle of Man" trip a few years ago saw us in some interesting conditions off Anglesey, stern sliding a big Ribcraft with 250 screaming horsepower doing nothing at all. Poly seemed to take it in his stride, but the rest of my crew have never set foot in a boat again!
I remember that day well, we spent most of the day vertical on the way back to Conway it's a good job we ventured out the next day or I would of sold my rib to the 1st person who wanted it
__________________
When you get to the end of your rope..tie a knot and hang on..!!
Aberdovey Ribs
B.I.O.C.Member
B.S. LEADER
tony t is offline   Reply With Quote
Old 03 October 2013, 21:34   #17
Redbay supporter
 
wiLlfish's Avatar
 
Country: UK - England
Town: onn de moov
Boat name: bote
Make: kevvin
Length: 4m +
Engine: jett dryve
Join Date: Jan 2010
Posts: 455
Quote:
Originally Posted by John Kennett View Post
the rest of my crew have never set foot in a boat again!
De waivs ad nuffink too doo wiv itt

Yorr croo jus didunt lyke yew
__________________
fuk mee crismus leeve wiv noe ankul tagg

Wher doo I beegin?😃
wiLlfish is offline   Reply With Quote
Old 03 October 2013, 21:36   #18
Member
 
colcreate's Avatar
 
Country: UK - England
Town: Cheshire
Boat name: Gollione
Make: Avon Searider 5.4
Length: 5m +
Engine: 90hp
Join Date: Jun 2010
Posts: 347
RIBase
You should try it towing your mates broken down rib with his divers on yours complete with 8 cylinders.....
__________________
colcreate is offline   Reply With Quote
Old 03 October 2013, 21:36   #19
Member
 
Exe treme's Avatar
 
Country: UK - England
Town: Exeter
Make: Highfield
Length: 5m +
Engine: Honda BF90
Join Date: Mar 2013
Posts: 272
Quote:
Originally Posted by Boatnomad View Post
Yep, deceptively fast moving water.........
Agree for a breaking wave, when duck diving.
__________________
Happy when wet!
Exe treme is offline   Reply With Quote
Old 03 October 2013, 21:38   #20
Member
 
Bigmuz7's Avatar
 
Country: UK - Scotland
Town: Glasgow
Boat name: stramash
Make: Tornado
Length: 5m +
Engine: Etec 90
Join Date: Feb 2006
Posts: 5,090
Quote:
Originally Posted by wiLlfish View Post
De waivs ad nuffink too doo wiv itt

Yorr croo jus didunt lyke yew
Haha .. he was determined to have retribution for years of spamming posters maybeez ye were selected
__________________
Bigmuz7 is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT. The time now is 15:11.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.