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Dock lines Q’s

Aug 17, 2013
Grampian G26 Ottawa/Gatineau
Hey everyone with the boat launch coming soon I noticed I’m lacking dock lines on my 26fter.

what length do I need and how many lines considering I don’t have mid ship cleats?

thanks in advance
Feb 21, 2013
Hunter 46 Point Richmond, CA
Recommend four 15 ft lines, one for each cleat, and one 25-30 ft for a spring line for a total of 5. My sailboat has one for each of 6 cleats and one spring line from the midship cleat or a total of 7.
Jan 19, 2010
Catalina 34 Casco Bay
Line size is a direct relationship to a doubled line being able to pass thru the open area under your cleat. You can spend money on lines that have had an eye spliced in them, or tie a double figure of eight in the end. The loop should be able to fit thru the opening under the cleat. Boat builders will size cleats to match lines. Dyneema will make great dock lines.
Aug 17, 2013
Grampian G26 Ottawa/Gatineau
I was thinking getting about 10 extra feet and splicing them myself, so I would need 100ft
Aug 17, 2013
Grampian G26 Ottawa/Gatineau
so nylon double braid would be best, is 10 extra feet enough or should I get a few extra feet to be safe?

Ward H

Nov 7, 2011
Catalina 30 Mk II Barnegat, NJ
so nylon double braid would be best, is 10 extra feet enough or should I get a few extra feet to be safe?
Go with three strand nylon because:
1. Double braid easily catches on dock and piling splinters. 3 Strand not as much.
2. Double braid does not stretch as much as 3 strand.
I tried both types of lines on my new to me O'day 25. The double braid had much less stretch and caused a hard jolt to the boat when stretched out. The 3 strand was much easier on the boat because the line stretched more instead of causing a hard jolt when it was stretched out.

1/2" lines is what I used and would suggest.
Oct 22, 2014
CAL 35 Cruiser moored EVERETT WA
It all depends.
If you have bull rail wood docks, like are popular on the BC coast, then @Ward H ’s suggestion of twisted 3 strand makes good sense.

I prefer nylon lines as @Davidasailor26 suggests because they stretch when the wind is howling softening the yin & yang pull of the boat Vs dock battle. Get good fenders to keep the hull clear of the dock.

Length is key. You need to have lines long enough to tie to the provided cleats but short enough so if the line falls into the water it will not reach the prop when hanging from the bow.

I've used 5/8 braided nylon on my dock for years. Definitely strong enough to keep the boat secure through the occasional winter gales. Our slip has large cleats which makes it easy to tie onto. My deck cleats are much better with 1/2 braided which I am switching to this season. Mostly because WM had a big dock line sale and I got the lines and colors I wanted at half price. Keep your eyes open for such opportunities.

I‘ve purchased a lot of my boat lines from a supply company serving arborists and loggers. They always seem to have a bin of end cuts less than 100ft in a variety of diameters and materials. Perfect for the small and mid sized boater at discount prices.


Nov 4, 2013
Tartan 3700 Seattle - Elliot Bay
I prefer 3 strand for stretchiness, and I also did not splice eyes in to the boat end this time so they could be released under load from the boat if I had to and I can adjust the lines from the boat side.

I’d go with at least four 15 ft lines and two 25 ft lines so I had bow and stern lines for both sides and springs for one side. For me, I have two extra springs so you have a complete set for both sides without moving anything around. In unfamiliar situations I find it easier to be set up for both sides, it’s less stress than moving stuff around at the last minute.
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Dec 25, 2014
Catalina 27 Pasadena, Md
To prevent the lines being caught and trashed by rough edges on the dock, get a few feet of hose, clothes washer works fine, cut enough to clear the distances the lines might scrape on and screw down to the edge of the dock under the lines. The lines will run freely and not fray.


Jul 21, 2020
Catalina 250 Black Hills
Good stuff here. I had a question as well: I've bought 100' of 3/8", 3 strand nylon, 4 snubbers and 4 thimbles (going to teach myself to splice) to make permanent dock lines for my C250. Need to pick up some shackles too. The harbor master suggested a loop of chain to tie to the dock cleats and I can't find any recommendations for chain size. Any suggestions?