Dock Lines

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Joined
Jul 6, 2012
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USA
Vessel Name
Alaskan Sea-Duction
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1988 M/Y Camargue YachtFisher
Need your opinion TF. I had all of my dock lines off the boat yesterday and they need to be replaced. Currently they are 3/4in soft nylon.

I am trying to decide if I really need 3/4in lines.

Not that I am really worried about cost, but why spend more than you have too.

Do I need 3/4 or 5/8?:confused:
 
In some marinas, boats sit nicely in a gale. In my marina the current runs through faster than any marina I have ever seen...enough to pull floating docks edges under water and have breakers on them.

So that's half the question.

Ultimately dock lines rarely snap if even close to their working load...it's generally chafe that spells disaster.

If you could eliminate chafe, 1/2 inch would be fine...it's what I had the first 3 years...and may go back to it with loops at either end so chafe is only 1/2 as bad.

But it ultimately is what you like for handling, looks and chafe. Strength unless continuously stressed isn't usually the determining factor.

Only caveat, is if you spring in hard or really stink at docking...heavier lines could be warranted....:D
 
Here is a PDF of size recommendations, on our 38' boat we use 5/8" for our normal travelling dock lines and use 3/4" on our home dock.
 

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too thick and short...they don't absorb much shock loading.


So that article saying a dock line is never to big is just another boat article writing done by someone with lots of theoretical knowledge and little actual. The problem is there isn't always an infinite number of cleats or pilings to make everything work out textbook.
 
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The larger the line the more difficult it is to properly tie them to the cleats; dock and boat. Like Scott says, rarely do our dock lines need near the breaking strength. Therefore, I use smaller lines now than I did when I first got the boat. 5/8-inch, braided nylon works fine for me on my 42-foot boat.
 
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A couple years ago we replaced all four . We used 3/4"line with chafe protection and added 4 mooring snubbers ( I won't say what everybody else calls them on the dock). I think we spent 600$ and it's way overkill . The snubbers were a real PITA to thread. It makes for comfort while docked but we could have got by with a lot less .The dock handlers duck when Joy throws them a line .
 

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Tom, I use all 5/8" line that I make sure are plenty long between my cleat and the dock cleat to absorb shock. I do have one 3/4" that someone gave me because it was too big for his boat but I haven't used it yet. I heard once a long time ago that dock lines are not meant to be LIFTING the boat, only to hold it in place, so you don't need extra heavy lines. More lines of a smaller diameter and longer are better than a few short lines that are thicker, IMHO.
 
When I purchased my 43 it had a mixture of 1/2, 5/8 and 3/4....I kept all of that to use when making day trips and temporarily docking. Replaced all of them with 5/8" x 25' braided nylon which works fine.
 
40' sailboat that displaces only about 23000 lbs fully loaded. I use 5/8" three strand for permanent dock lines. I inspect these periodically for wear and replace as needed. They are ugly but functional.

I keep 5/8" braid on board to use when we are away from our home dock. I like the braid since it is easy to handle and easy on the hands. It never gets much wear so lasts forever.

5/8" is more than I likely need, but it provides a very nice margin and isn't so big as to make putting two lines on a cleat impractical.
 
too thick and short...they don't absorb much shock loading.

The larger the line the more difficult it is to properly tie them to the cleats; dock and boat.

+1 on the above, and the rest of the similar comments.

I think the PO of my boat had a secret fantasy to be a tug boat captain. I found all kinds of 1" and 3/4" line that was just too bulky to handle and difficult to tie off to many of the cleats we encountered on the delivery run.

It all went (except for a few pieces of 3/4" that were in good condition) and was replaced by 5/8" 3-strand soft nylon. I never once regretted it.

I know the discussion about laid vs braid vs brait line can get religious, but I find I like the ease of working with laid line, along with the extra shock loading. Plus, I can replace it all without having to take out a loan.
 
Trawlers need 3/4" three strand nylon lines. White only. With bowlines instead of spliced loops. Unless the loops are hand spliced.

Trawlers are he-man boats. Get with the program.
 
It depends on the size cleats you have on your boat. Generally, you should use 1/16" line per inch of cleat. Therefore an 8" cleat should use 1/2" line and a 10" cleat would use 5/8" line. You can usually go one size larger or smaller and still get it to hold properly on a given cleat. But you probably do not want to go with 5/8" on a 6" cleat. Or 3/8" line on a 10" cleat. This also assumes that you boat has properly sized cleats.
 
While we're at it, do you use white or colored?

A couple of pieces of information. Double braid is stronger than the 12 strand multi-braid. Also, white is stronger than colors.
 
A lot depends on how it is secured and what is used as terminal ends. If you are using a knot or a splice. While it is true that chaffing will be the biggest problem an immediate loss of strength is determined by the knot. If you don't splice a bowline is the strongest.
 
While we're at it, do you use white or colored?

A couple of pieces of information. Double braid is stronger than the 12 strand multi-braid. Also, white is stronger than colors.

What? White, no way it doesn't match, mine are black.......:socool:
 
While we're at it, do you use white or colored?

A couple of pieces of information. Double braid is stronger than the 12 strand multi-braid. Also, white is stronger than colors.

White for my permanent dock lines, 3 strand that I splice myself.

Black for the double-braid that we keep on the boat, those were pre-spliced. I splice double braid, but it is actually cheaper to buy ready made dock lines than to buy the double braid and make them up yourself.
 
White vs colors on dock lines?

While we're at it, do you use white or colored?

A couple of pieces of information. Double braid is stronger than the 12 strand multi-braid. Also, white is stronger than colors.

Why is white stronger than colored lines?
 
Why is white stronger than colored lines?

The process of dying I suspect. It weakens them ever so slightly. I would not have suspected it, but I certainly know with fabrics, dying can stretch them sometimes. The problem with that is that at some point fabric will shrink back to it's previous size. I seriously doubt though that the strength difference is enough to ever be noticed. Just something I've heard from rope people and seen on some of their websites. Here's what Rope Inc/Nance and Underwood say.

"When making a choice of line for your boat, keep in mind that 12-strand (Mega braid or Brait) line is not as strong as double braid line and colored line is not as strong as white line."

I was first told by an older captain and thought he was just pulling my leg.

I imagine this information is of no use other than a very strange trivia game.
 
I found this explanation on another site:

"The molecules for the dye do take up some room, that rope fibre now can't occupy. But, usually the losses are nominal."

I take it what he's saying is that a white 5/8" is 5/8" rope and a colored one is and 199/320" and 1/320" dye or something like that.
 
44' Swift Trawler - large amount of windage area...........
5/8" double braid - home dock lines
5/8" double braid - travel lines - two colors on the bow and stern - no confusion with my boat owner when docking. 'Use the red", "Use the black", etc. No sense having a mad Captain when you are all docked and looking share an adult beverage!!!
 
Good info on the color differences, I never knew that and wonder if some is due to the sunlight/reflective qualities.
 
Good info on the color differences, I never knew that and wonder if some is due to the sunlight/reflective qualities.

Well, that gets into another issue and there are differences in how various colors handle sun.
 
Well now I wished there were Florissant colors
 
Well, that gets into another issue and there are differences in how various colors handle sun.

Yes, I would have thought the sunlight affect would favour white, as absorbs less rays, but having said that, mine are now all black, 'cause they look better...
:)
 

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I use all 5/8 double braided dock lines. They fit my cleats well and I CAN get 2 on a boat or typical dock cleat, but I think any bigger and there would definitely be difficulty with 2 lines on a cleat. I have some 25's and some 35's. I like to use the 35's for spring lines. As others have noted, can't imagine needing more strength at a dock unless it was during a hurricane. They're all dark green. Hope they don't break. :rofl:

Ken
 
The larger the line the more difficult it is to properly tie them to the cleats; dock and boat. Like Scott says, rarely do our dock lines need near the breaking strength. Therefore, I use smaller lines now than I did when I first got the boat. 5/8-inch, braided nylon works fine for me on my 42-foot boat.

:thumb::thumb:
Also I
 
OK. This seems to be a good place to ask.

Where should I use my 3 strand nylon that stretches a lot versus my 5/8" double braid.

My issue is too many times in bouncy waters the boat is lifting the dock producing very unpleasant rhythm.

I'm thinking spring lines should be the braided lines and the bow and stern lines should be nylon.

Thoughts?
 
Where should I use my 3 strand nylon that stretches a lot versus my 5/8" double braid.

My issue is too many times in bouncy waters the boat is lifting the dock producing very unpleasant rhythm.

Use 3-strand laid line for all dock lines. The extra "stretch" will help to absorb the shock loads.

Too many people read that brait or braid is "stronger" than laid line, and confuse that with "better". As was pointed out, you really shouldn't worry about the breaking strength of the line. More likely it will chafe through, or the fittings will pull out of the dock or the deck, or knots and bends will come undone. All of those things are helped by reducing shock loading.

The other thing that will help a lot with your problem of lifting the dock is to make every dock line as long as possible, for the same reason.

This can sometimes be hard to accomplish for bow and stern lines. I've always tied from the "far" side of the stern, and if I can I'll bring the bow line far forward of the cleat. Never, never leave a boat unattended with a short breast line.

Walking the docks, I'm always amazed by how many people have apparently lever been taught these basic concepts.
 
The other thing that will help a lot with your problem of lifting the dock is to make every dock line as long as possible, for the same reason.

Just to be clear, this is a great recommendation for two reasons; 1) By tying off to the far side stern cleat if possible, you flatten the angle of the line to the dock cleat. This creates less lifting affect which reduces the chance of the cleat failing 2) the longer the line, the more stretch you have.
 

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