Reply
 
Thread Tools Search this Thread
 
Old 15 May 2014, 13:13   #1
Member
 
Country: USA
Town: Boston
Boat name: Floating RIB
Make: AB
Length: 4m +
Engine: 98 Johnson 3cyl 35hp
Join Date: Sep 2012
Posts: 25
four blade prop for following seas?

My boat seems to really bog down in following seas, to the point that it scares me a little. It is a 13' AB console with 35hp Johnson.

Is there any point in trying out a four-blade prop to minimize the risk or am I just underpowered, period?
__________________

__________________
porkpiehat is offline   Reply With Quote
Old 15 May 2014, 13:59   #2
Member
 
Country: UK - England
Town: Bristol
Make: Ribcraft
Length: 5m +
Engine: Yamaha
Join Date: May 2006
Posts: 4,194
underpowed
__________________

__________________
Member of S.A.B.S. West Country Division
matt h is offline   Reply With Quote
Old 15 May 2014, 14:19   #3
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
Quote:
Originally Posted by matt h View Post
underpowered
I agree. Underpowered.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 15 May 2014, 16:53   #4
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
When you say bog down, are you talking about the stalling feeling you get climbing the back of a swell? While you may well be underpowered, I think all boats get that feeling to some degree; it's a function of driving the boat essentially "uphill" just after losing forward momentum from bashing into the back face of the wave.

jky
__________________
jyasaki is offline   Reply With Quote
Old 15 May 2014, 22:59   #5
Member
 
Country: USA
Town: Boston
Boat name: Floating RIB
Make: AB
Length: 4m +
Engine: 98 Johnson 3cyl 35hp
Join Date: Sep 2012
Posts: 25
And what if I'm going to be towing out divers and equip for scuba? Any benefit for a four-blade then?
__________________
porkpiehat is offline   Reply With Quote
Old 16 May 2014, 05:23   #6
Member
 
Landlockedpirate's Avatar
 
Country: UK - England
Town: St Helens
Boat name: Wine Down
Make: Maxum
Length: 8m +
Engine: Inboard
Join Date: Apr 2012
Posts: 934
After many years spending a small fortune and playing with shiny props, I have come to the conclusion that 99% of the time the factory fitted prop works best for general use in a standard powered leisure application. The manufactures do a lot of testing of props, they know what they are doing.

On an underpowered boat like yours (sorry to be blunt) I would leave it alone, I'm pretty sure that a 4 blade prop, regardless of size, will make thingsworse.

BTW,the current use for 1 of my props that I was convinced would transform my boat is a little less glamorous

__________________
Landlockedpirate is offline   Reply With Quote
Old 18 May 2014, 07:05   #7
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
On lower powered boats prop choice really doesn't reap the same rewards as higher HP models.

One thing I did find years ago when I was playing around with props on a 5.2m RIB with an 80hp engine was that if I was going out on a rough day I would replace the 17" pitched prop with a 15" pitched prop as it would give me better hole shot and quicker reaction times to wave conditions. This obviously dropped my WOT speed but increased handling capabilities especially in following Sea's.

So if you're still looking at props I would suggest a lower pitched one rather than a fancy one.
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 19 May 2014, 03:27   #8
Member
 
Cookee's Avatar
 
Country: UK - England
Town: Salcombe, Devon, UK
Boat name: BananaShark
Make: BananaShark
Length: 10m +
Engine: 2xYanmar 260 diesels
Join Date: Mar 2003
Posts: 4,225
Quote:
Originally Posted by Hightower View Post
On lower powered boats prop choice really doesn't reap the same rewards as higher HP models.

One thing I did find years ago when I was playing around with props on a 5.2m RIB with an 80hp engine was that if I was going out on a rough day I would replace the 17" pitched prop with a 15" pitched prop as it would give me better hole shot and quicker reaction times to wave conditions. This obviously dropped my WOT speed but increased handling capabilities especially in following Sea's.

So if you're still looking at props I would suggest a lower pitched one rather than a fancy one.
+1! Good advice!!!!!
__________________
Cookee
Originally Posted by Zippy
When a boat looks that good who needs tubes!!!
Cookee is offline   Reply With Quote
Old 04 July 2015, 11:46   #9
Member
 
Country: USA
Town: Boston
Boat name: Floating RIB
Make: AB
Length: 4m +
Engine: 98 Johnson 3cyl 35hp
Join Date: Sep 2012
Posts: 25
And the engine didn't rev too high with the lower pitch?
__________________
porkpiehat is offline   Reply With Quote
Old 04 July 2015, 20:17   #10
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
If you're out in rough stuff, you rarely run at WOT. It's on again off again trying not to beat yourself up.

jky
__________________

__________________
jyasaki is offline   Reply With Quote
Reply

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 21:48.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.