Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-09-2014, 18:45   #1
Marine Service Provider

Join Date: Dec 2009
Location: St Augustine, FL
Boat: Woods Vardo 34 Cat
Posts: 2,825
Outboard Planing Fins

Have used the 2 piece Davis plastic fins in the past, but wondering if there are better options like some of the one piece alloy ones?

I have a 1977 .evinrude 9.9 on a Caribe C-9. The stern REALLY squats when trying to get on plane and with only about 320 in crew weight it struggles to get fully flat when planning. With around 200 lb of crew weight it is quite fast.

Might need a different prop and 15 hp carb as well.
__________________

__________________
Check out my MoJo: Facebook.com/mojomarine1
Boatguy30 is offline   Reply With Quote
Old 28-09-2014, 19:44   #2
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Outboard planning fins

We had the Doelfins on several previous outboards and have the SE Sport200 on our current outboard: Amazon.com : SE Sport 200 Hydrofoil, fits 8 hp - 40 hp engines : Boating Equipment : Sports & Outdoors

I think the SE may perform better, but it is difficult to judge because it is on a completely different engine. It definitely is less cumbersome when moving the engine around off the dinghy and catches less weeds.

There are other types that look like an entire re-engineered lower unit, but I don't know how they work. Seems like the best thing would be to get a new larger outboard before bolting on those expensive contraptions.

However, I think you are expecting WAY too much from a 1977 Evinrude 9.9 on a Caribe C-9 with 320# of crew.

Mark
__________________

__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 28-09-2014, 19:47   #3
Long Range Cruiser
 
MarkJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,828
Images: 25
Re: Outboard planning fins

1977? My grandmother is younger.


Get the fins but a coffin may be better.
__________________
Notes on a Circumnavigation.
OurLifeAtSea.com

Somalia Pirates and our Convoy
MarkJ is offline   Reply With Quote
Old 28-09-2014, 20:09   #4
Marine Service Provider

Join Date: Dec 2009
Location: St Augustine, FL
Boat: Woods Vardo 34 Cat
Posts: 2,825
Re: Outboard planning fins

She runs sweet. A very low hour fresh water motor. I'm planning a big joint birthday party for 2017 perhaps in Musket Cove. Just pulled the Caribe from the trash Thursday so hard to say if that'll make it, but only needed 2 patches so far.

I'd go on, but I'd sound even more WT.
__________________
Check out my MoJo: Facebook.com/mojomarine1
Boatguy30 is offline   Reply With Quote
Old 28-09-2014, 20:15   #5
Marine Service Provider

Join Date: Dec 2009
Location: St Augustine, FL
Boat: Woods Vardo 34 Cat
Posts: 2,825
Re: Outboard planning fins

Just ordered a stingray jr "new" off eBay for $21, free shipping. Will see how it does. Considered the SE 200 but saw some posts on fishing forums they work best on 20 horses plus. They probably all work the same roughly on this application. Will keep a lookout for another junky caribe with 37 y/o motor to speed test with.
__________________
Check out my MoJo: Facebook.com/mojomarine1
Boatguy30 is offline   Reply With Quote
Old 15-11-2014, 06:41   #6
Registered User
 
sparrowhawk1's Avatar

Join Date: Jan 2014
Location: Miami Beach Fl
Boat: Colombia Cc 11.8
Posts: 1,252
Re: Outboard planning fins

Quote:
Originally Posted by Boatguy30 View Post
Just ordered a stingray jr "new" off eBay for $21, free shipping. Will see how it does. Considered the SE 200 but saw some posts on fishing forums they work best on 20 horses plus. They probably all work the same roughly on this application. Will keep a lookout for another junky caribe with 37 y/o motor to speed test with.
What words did you use for your search? Thanks.
__________________
sparrowhawk1 is offline   Reply With Quote
Old 15-11-2014, 07:54   #7
Senior Cruiser
 
Roy M's Avatar

Cruisers Forum Supporter

Join Date: Feb 2007
Location: Southwestern Yacht Club, San Diego, CA
Boat: Searunner 40 trimaran, WILDERNESS
Posts: 3,041
Images: 4
Re: Outboard planning fins

I purchased a Davis Whale Tail, the aluminum unit, for my propane Lehr 15, on an AB RIB, but haven't had time yet to install it. I plan on putting it on temporarily, removing it and doing a measured mile a couple times, then, the same day, pop the Tail on and do a comparison. Should be interesting.
__________________
Roy M is offline   Reply With Quote
Old 16-11-2014, 02:17   #8
Registered User
 
sparrowhawk1's Avatar

Join Date: Jan 2014
Location: Miami Beach Fl
Boat: Colombia Cc 11.8
Posts: 1,252
Re: Outboard planning fins

I just ordered 1 ( hydrofoil by shoreline marine) on amazon for $15.60 searched outboard hydrofoil and on the lower priced ones "searched" buying options and I got one used- free shipping but I had to join Amazon Prime(for free)
__________________
sparrowhawk1 is offline   Reply With Quote
Old 16-11-2014, 05:37   #9
Marine Service Provider

Join Date: Dec 2009
Location: St Augustine, FL
Boat: Woods Vardo 34 Cat
Posts: 2,825
Re: Outboard Planing Fins

The stingray seemed to make a very small difference. It does keep the stern from squatting as much going on and coming off of plane but make little difference if any as far as the time to get on plane.

In hindsight, this was pretty much my experience with the Davis fins in the past. I think they only really help when you have a marginal planning setup it can maybe give you that extra little bit. But certainly does not make anywhere the difference the companies claim.
__________________
Check out my MoJo: Facebook.com/mojomarine1
Boatguy30 is offline   Reply With Quote
Old 16-11-2014, 05:55   #10
Senior Cruiser
 
Captain Bill's Avatar

Cruisers Forum Supporter

Join Date: Apr 2008
Location: On the boat
Boat: Endeavourcat Sailcat 44
Posts: 2,313
Re: Outboard Planing Fins

I put the Sting Ray Jr. on my 15 hp Suzuki and my 10'4" Achilles Rib. It didn't make very much difference with two people on board, but it made a huge difference with one person on board. With only one person on board the RIB would squat and the bow would come up extremely high. You actually had to give it power very slowly and it took a while to get the bow down and the boat on a plane. With the Sting Ray Jr. It pops up on a plane very quickly. It also stopped some air entrainment I was getting around the prop when trying to get on a plane in choppy water. I don't think it did anything for me as far as top speed goes, and it may have even cost me a little. It has to add some drag that wasn't there before.
__________________
Captain Bill is offline   Reply With Quote
Old 22-11-2014, 19:35   #11
Registered User
 
sparrowhawk1's Avatar

Join Date: Jan 2014
Location: Miami Beach Fl
Boat: Colombia Cc 11.8
Posts: 1,252
Re: Outboard planning fins

Quote:
Originally Posted by sparrowhawk1 View Post
I just ordered 1 ( hydrofoil by shoreline marine) on amazon for $15.60 searched outboard hydrofoil and on the lower priced ones "searched" buying options and I got one used- free shipping but I had to join Amazon Prime(for free)
Installed my fin made a huge difference. I have a dinghy that is basically a sailboat, 10 foot long with an 8 horsepower on it and just above idle throttle it would start squatting. Now it stays flat and I can go fast but I'm not sure it's truly planning. I ordered one for my friend and the price went up to 19.19 after tax. But well worth it. And they're listed as used but they're brand new with a very slightly damaged box
__________________
sparrowhawk1 is offline   Reply With Quote
Old 26-12-2014, 19:42   #12
Marine Service Provider
 
rourkeh's Avatar

Join Date: Jun 2010
Location: Northern Caribbean
Boat: Cheoy Lee, 44 Cutter. Dolce Far Niente
Posts: 403
Re: Outboard Planing Fins

If these fins on the lower unit actually worked don't you think the outboard manufacturers would have incorporated them into their lower units to make them perform better? Funny that not a single company produces an outboard with a finned lower unit!!!!
__________________
rourkeh is offline   Reply With Quote
Old 26-12-2014, 22:02   #13
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,742
Re: Outboard Planing Fins

Quote:
Originally Posted by rourkeh View Post
If these fins on the lower unit actually worked don't you think the outboard manufacturers would have incorporated them into their lower units to make them perform better? Funny that not a single company produces an outboard with a finned lower unit!!!!
But they do work.

I installed a large set on my 25 horsepower Mariner, and the dinghy now planes at about half the RPM as previously, giving a far more economic and comfortable cruising speed. Vast difference, at least on my boat.
__________________
Dockhead is online now   Reply With Quote
Old 27-12-2014, 06:06   #14
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,579
Images: 240
Re: Outboard Planing Fins

Quote:
Originally Posted by rourkeh View Post
If these fins on the lower unit actually worked don't you think the outboard manufacturers would have incorporated* them into their lower units to make them perform better? Funny that not a single company produces an outboard with a finned lower unit!!!!
A very good question.
Perhaps (tho' I doubt it) a patent issue?

* Or offered them as an OEM accessory.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 27-12-2014, 06:31   #15
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 7,925
Re: Outboard Planing Fins

Quote:
Originally Posted by rourkeh View Post
If these fins on the lower unit actually worked don't you think the outboard manufacturers would have incorporated them into their lower units to make them perform better? Funny that not a single company produces an outboard with a finned lower unit!!!!
Yeah, you would think, but clearly such behavior does not hold in the actual market place. Take just about any complex thing you buy (motors, boats, cars, computers, cell phones...) and there is significant after market accessories business (cell phone accessories is a massive market for example).

The OEM lower units are finned enough to prevent cavitation and these after market fins do make a difference. I've run the same engines on dinghys with and without and the difference is very apparent. The main advantage from my perspective is much quicker planing.
__________________

__________________
belizesailor is online now   Reply With Quote
Reply

Tags
outboard

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
How Many of You are using Doel-fins, or other stabilizing fins? montenido Auxiliary Equipment & Dinghy 14 20-09-2013 11:18
For Sale or Trade: Large Wetsuit and Fins Eco Voyager Classifieds Archive 0 13-10-2010 18:39
Trip Planning and Routing Software / Tools wesaint Atlantic & the Caribbean 9 30-05-2010 08:27
Trip Planning AnotherSailorman General Sailing Forum 7 27-05-2009 13:16
Mercury outboard book? Or just outboard? Jack Long The Library 2 17-09-2008 09:33



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:08.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.