Reply
 
Thread Tools Search this Thread
 
Old 01 May 2019, 06:30   #1
Member
 
Country: UK - England
Town: Shropshire
Length: 3m +
Engine: 15
Join Date: Apr 2019
Posts: 13
Does sib length make much difference to speed?

Say a 3.2 vs a 3.8 with a 15, 9kg weight difference. would there be noticeable difference in speed? Both with 2 up. Final newbie question I promise
__________________

__________________
Barter is offline   Reply With Quote
Old 01 May 2019, 06:53   #2
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 5,491
not much in speed terms IMO but in size well worth the 3.8, ride wise length is better but it's all down to sea conditions as is speed
__________________

__________________
jeffstevens763@g is offline   Reply With Quote
Old 01 May 2019, 06:54   #3
Member
 
Country: UK - England
Town: Sussex
Boat name: Bombard, Y-162
Make: Aerotec 380, Y-Class
Length: 3m +
Engine: Mercury Mariner 15hp
Join Date: Jul 2010
Posts: 3,010
This will all cross over with your main topic so better to keep it all together in one.

A lot of variables though - hard floor, air floor, deep V, medium V, flat floor? All affect speed a lot as do trim and weight distribution. But like for like it won't differ that much.

Much more important than 1/2 to 1 knot here or there at WOT is choosing the right length/floor type boat for the conditions/use/crew/transport.

In typical UK coastal conditions in the summer in a SIB in F3/F4 then you won't be at WOT lots of the time anyway.
__________________
Max... is offline   Reply With Quote
Old 03 May 2019, 12:34   #4
Member
 
Country: UK - England
Town: Lincolnshire
Boat name: Mousetrap
Make: Zodiac Cadet 310S
Length: 3m +
Engine: Mariner 4 stroke 9.9
Join Date: Sep 2014
Posts: 341
On perfectly flat water, the difference at planing speed in a straight line may not be all that much.

However, in a chop, or a big swell, the extra stability, dryness, and confidence of having a bigger hull will probably translate into higher average speed over a journey.
__________________
My novel, "Bridge of Otherwhere" 2018 by Michael Wilkinson, now available for download on Kindle.TinyURL.com/Bridge-of-Otherwhere
Mikefule is online now   Reply With Quote
Old 03 May 2019, 13:37   #5
Member
 
chipko's Avatar
 
Country: UK - England
Town: Up North and right a bit
Make: XS500/Bic245
Length: 5m +
Engine: Mariner60/3.5 Hon2.3
MMSI: 239711398
Join Date: Sep 2013
Posts: 479
Does sib length make much difference to speed?

All good advice above.

9 kilo difference and 3.2 to 3.8...assume talking Honwave’s...so both same hull.

With same hp motor and only 9 kilo weight disadvantage then the 3.8 will get on the plane quicker than 3.2.

The extra length of the 3.8 will translate into much faster/ comfortable average speeds in typical uk chop/swell regardless of motor. Go 3.8.
__________________
chipko is offline   Reply With Quote
Reply

Tags
sib

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 01:54.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×