Lobster Pots & a prop protection wire from Keel to Skeg? - Page 3 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > General Interest Forums > General Discussion (sailing related)
 Not a Member? 


Like Tree3Likes
Reply
 
LinkBack Thread Tools
  #21  
Old 07-27-2012
hellosailor's Avatar
Senior Member
 
Join Date: Apr 2006
Posts: 10,057
Thanks: 0
Thanked 50 Times in 49 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

The premise behind a Kort nozzle is that it prevents any propwash from slipping off the ends of the prop blades, i.e. the same way that vertical 'winglets' at the end of aircraft wings prevent airflow from slipping off the ends.

I'm surprised to see round-bladed props in a Kort nozzle, I would have thought that a blade which followd the same curve as the inside of the nozzle, allowing for small tolerance between them, would be better again still. (Or a waste of money since there's noplace for the lost flow to go?)

Of course the beauty of a cage or a nozzle is that if something gets jammed in there, now you've REALLY got a jam.
Reply With Quote Share with Facebook
  #22  
Old 07-27-2012
DivingOtter's Avatar
Otter
 
Join Date: May 2012
Location: Toms River NJ
Posts: 163
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2
DivingOtter is on a distinguished road
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

Very true that the main premise for a Kort Nozzle is Thrust Vectoring, However it DOES help protect the wheel in certain instances especially from lateral contact and ingesting lines or debris from the fluke tips inward.
Reply With Quote Share with Facebook
  #23  
Old 07-27-2012
Senior Member
 
Join Date: Jul 2007
Location: Truckee, CA
Posts: 5,829
Thanks: 2
Thanked 89 Times in 87 Posts
Rep Power: 7
dabnis is on a distinguished road
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

Quote:
Originally Posted by DivingOtter View Post
your most likely referring to a Kort Nozzle.They are usually on commercial vessels and do not work as effectively as many people think. All i can say is during all my underwater inspections they are massive. When im tending to a wheel I actually climb inside of them

Attachment 11748
I have read about and seen pictures of Kort Nozzles but that is not what I had in mind. The commercial boats I have seen on the west coast had many varations of the picture in DaddyO's post:

Propellor Guard - Trawler Forum

The one in the picture is kind of primitive but I suppose it gets the job done? Something for a sailboat could be much smaller, simpler, and made of much lighter material, perhaps some sort of plastic? Maybe something like a short skeg on each side ahead of the prop, epoxied to the hull?

Paul T
Reply With Quote Share with Facebook
  #24  
Old 07-27-2012
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 8,264
Thanks: 6
Thanked 89 Times in 86 Posts
Rep Power: 6
Minnewaska will become famous soon enough Minnewaska will become famous soon enough
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

In my humble opinion, there is a bit of witchcraft suggested here. What works is:

Plan A - see and avoid

Plan B - shaft line cutter.

I don't think it is or can be more complex than that. If you don't see and avoid, nothing is perfect.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Reply With Quote Share with Facebook
  #25  
Old 07-27-2012
DivingOtter's Avatar
Otter
 
Join Date: May 2012
Location: Toms River NJ
Posts: 163
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2
DivingOtter is on a distinguished road
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

I think this is one of those " you play, you pay" sort of issues.
Reply With Quote Share with Facebook
  #26  
Old 07-27-2012
hellosailor's Avatar
Senior Member
 
Join Date: Apr 2006
Posts: 10,057
Thanks: 0
Thanked 50 Times in 49 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

Paul, that's also called a "cage" or propellor cage. I've seen them on dive boats as well, where the captain wants to protect divers in the water in case he has to start the engine.
Reply With Quote Share with Facebook
  #27  
Old 07-27-2012
Senior Member
 
Join Date: Jul 2007
Location: Truckee, CA
Posts: 5,829
Thanks: 2
Thanked 89 Times in 87 Posts
Rep Power: 7
dabnis is on a distinguished road
Re: Lobster Pots & a prop protection wire from Keel to Skeg?

Quote:
Originally Posted by hellosailor View Post
Paul, that's also called a "cage" or propeller cage. I've seen them on dive boats as well, where the captain wants to protect divers in the water in case he has to start the engine.
Ah, yes a cage. That is a better description. No doubt a cage for a sailboat would take some brainstorming. I was thinking about a set of "fingers", maybe about four of them, two near the shaft and two just a little wider than the prop,
mounted six inches or so forward of the prop. They could be shaped something like a skeg and swept back somewhat and epoxied to the hull. I don't think they would create much drag or turbulence for the prop? They could be made out of some dense, tough type of wood like Oak or Ash? And maybe a line cutter as backup?

Paul T
Reply With Quote Share with Facebook
  #28  
Old 07-27-2012
Maine Sail's Avatar
Senior Member
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,140
Thanks: 8
Thanked 88 Times in 62 Posts
Rep Power: 15
Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice
Re: Lobster Pots & a prop protection wire from Keel to Skeg?


When sailboats snag a pot on a shaft or rudder, and think they are doing a favor by trying to get it off without cutting it, they usually are only making it worse.

Wire traps are very light weight and dragging ten of them is no problem for a boat with sails up or one in wind and current. Often times what happens is the boat drifts, and drags the the string across a few others. This makes a HUGE, HUGE mess!!

I used to run pot buoys on both ends of my string, as most all fisherman do. Not once did I ever loose both ends at the same time. Replacing a pot buoy is FAR cheaper than loosing 300 feet of warp to a tangle and the time involved in re-rigging a string..


As far as toggles go the old excuse is that they are used to keep the line from tangling the bottom or a rock. This is pure BS!! This excuse is worn out and is not even close to why they actually use them. Most fisherman use them out of habit & history and because the more they use them the more pot buoys they lose due to line cuts. It is a self fulfilling/defeating idea. If they used no toggles as they do in Casco Bay they would lose a LOT less pot buoys. Sadly old habits die hard and fishermen are a stale & crusty old bunch whom are also very, very resistant to change. They keep using toggles so that when the main pot buoy gets cut they can still boat hook the toggle.

If you want to see just how much BS the "keep the line off the bottom theory is" just note how many of the toggles are still floating & laying rather flat on the surface at high tide. By "theory" that toggle should be 10-14 feel below the surface at high tide to keep the line off the bottom.

I have actually argued against the use of these toggles, from a boater safety standpoint, and as an ex-commercial fisherman, to my state Senator, but he was unwilling to submit a bill to ban them. There is ZERO legitimate reason for their use, they way they are currently used, and they only lead to more pot buoys being cut off. Thus the fisherman think they are a good idea and the viscous circle begins again..

Far less pot buoys are cut off in areas where they don't use them. In my thousands & thousands of pulls, without toggles, I never once had a line snag the bottom, ever. Toggles are pure BS!


Here are a few tips on how to deal with lobster pots.

#1
ALWAYS try to pass to the down current, down wind or down tide side of the pot. Never intentionally pass above a lobster pot unless you absolutely know you have the room to do so! They have an uncanny way of letting you know which way is up current, wind or tide and which way is down. Follow the stick or the wake!

This one is pointing or angled towards "down tide" so you'll pass to where the stick leans or points. This is about a 1.5 knot current at the mouth of Penobscot Bay and well off Vinalhaven and Northhaven Islands. We were miles from the nearest land yet Pen Bay has HUGE amounts of water to spill and the currents can run miles out to sea.. NEVER EVER intentionally pass a pot like this to the up tide or up current side!!!

#2 Wear polarized sunglasses!!! My daughter had grabbed my Maui Jim's and got "snack goo" all over them. Rather than clean them I stupidly grabbed my "guest" pair of sunglasses, a non-polarized pair of Ray Ban's.

As you can see we almost hit this pot that was pulled under by the tidal current! My maneuver was late because I never saw it until the absolute last second. At that point I had no choice but to turn hard stbd and pass to the up-current side which as you can see could have been very dangerous. Again, WEAR POLARIZED SUNGLASSES! You will see these submerged pots well before you will with non-polarized glasses. My camera had a polarizing filter so I snapped that as we passed.

#3 just because it's calm does not mean the pots are not still trying to tell you something. Current & tide still exists even in flat glass conditions. Note the direction of the "sticks"...

#4 It may be calm but this pot has a decent current flowing by it. Just look at the "wake" made by the buoy..


Quote:
I passed too close to a lobster guy and he was swearing at me and really pissed how do I avoid pissing these guys off?
Look for his or her "colors" then spot his/her pots on the water and as a courtesy, and for your own safety, these guys are cowboys, get away from them as the boat is likely moving to the next pot that matches the displayed colors!

Lobstermen are required to display their "colors" or one of their own pot buoys mounted up high on the boat so it can be seen.
Note the pot buoy above the radome:

Note the "colors" on the port side wheel house roof:

Note the "colors" laying on the wheel house roof behind the spot light & hanging dead center also look on the water and you'll see two more of his/her pots.. stay away from them:

Pot buoy/colors located on stern end port side of wheel house roof:

HDChopper likes this.
__________________
______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.


Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lobster pots dylanwinter1 General Discussion (sailing related) 12 06-22-2012 09:03 PM
Night Sailing/motoring and Lobster Pots RobGallagher Learning to Sail 9 09-09-2009 01:13 PM
Vid - Coast Guard does NOT worry about lobster pots c40eb General Discussion (sailing related) 5 07-15-2009 08:43 PM
Avoiding & Sailing W/Lobster Pots & Lobstermen Maine Sail General Discussion (sailing related) 6 09-11-2008 11:03 AM
Problem picking up Lobster pots with rudder sailphoto Seamanship & Navigation 66 01-14-2007 10:57 PM


All times are GMT -4. The time now is 02:57 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012