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Old 19 February 2014, 04:20   #1
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Length...does it really matter?

Hi Folks

Probably a dumb question but thought I'd ask the cumulative knowledge of Ribnet for their experiences.

I'm upgrading my RIB and currently looking at either a 5.5m or a 6m LOA from the same manufacturer - same hull.

The engine will be the same, the beam is the same as is the deadrise.
The dry weight difference is approx 50KG so (I assume but might wrong) it shouldn't affect the grunt available too much - the internal fuel tanks are the same on both boats too so no weight difference there either.

How much of a difference will 0.5m LOA realistically make or will it simply offer a little more deckspace?

Thanks in advance
Chunk
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Old 19 February 2014, 04:40   #2
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Have a read at the Forth Jubilee cruise thread - especially the bit when we motored through the Kincardine bridge into a monster wind vs strong current lump.

The group I was with had an SR4 , myself at 5m and a 6& a bit m rib. As the river widened as we motored downstream of the bridge the wavelength & shape changed. Betwween the three of us, one was always slapping the next wave (hard), one riding peak to peak like a magic carpet and the other "going up & down the hills".

What I'm saying is that there will always be a sea state that makes your particular boat uncomfortable or hard work. Yes, you could argue a longer boat is more likely to straddle bigger waves, but it's a big complex equation with the real definition of "a difference" lying with you & your crew's perceptions.


That probably wasn't much help tfior your decision, but if all other things were equal as you are implying (you'll probably be carrying more weight as fuel than the weight difference) and it was still going to fit the place I wanted to park it, yeah, I'd go up 0.5m for the deck space......
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Old 19 February 2014, 04:44   #3
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Never underestimate what a bit of extra LOA will do. You'll certainly NOTICE it. I'd guess mainly in extra deck space and a slightly better ride. Bound to knock a knot or so off the top end. I'd do it

Two boats in the pic below - 16m and 8.5m. Double the LOA make a world of difference
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Old 19 February 2014, 05:10   #4
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Quote:
Originally Posted by Chunk View Post

How much of a difference will 0.5m LOA realistically make or will it simply offer a little more deckspace?
Redbay make a 6.1m and a 6.5m and believe me that 0.4m makes a big difference to their sea keeping and sense of space onboard.

The downside is that the extra length can lead to issues when launching/recovery, towing and parking.
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Old 19 February 2014, 05:36   #5
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Thanks for the great replies

Kind of matches my thoughts so good to get confirmation from more experienced bods. I will mostly be launching single handed from a relatively shallow angled beach so that is also at the back of my mind...my current 4.7m is simple to launch and recover single handed.

What the hell...go for the 6m. If I need to wait 30 mins for the tide to "float the boat" its not the end of the world
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Old 19 February 2014, 06:55   #6
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If the hull beam is the same, and the engine leg is the same, I'd imagine that draft will be very similar? The extra .5m will mean your engine is .5m further out to sea at launch...
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Old 19 February 2014, 08:02   #7
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Quote:
Originally Posted by Chunk View Post
Thanks for the great replies

Kind of matches my thoughts so good to get confirmation from more experienced bods. I will mostly be launching single handed from a relatively shallow angled beach so that is also at the back of my mind...my current 4.7m is simple to launch and recover single handed.

What the hell...go for the 6m. If I need to wait 30 mins for the tide to "float the boat" its not the end of the world
Yes, always go as big as practically and financially possible, sea keeping, deck space, safety, etc etc
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