What type of leash (knee or ankle) do you use in Supsurfing and what is your favorite model/brand for quality, solidity and comfort?
I love leashlok
leashlokhawaii.com.
They have a great waist leash if you are so inclined. Plus they have nylon leash attachment that I find very solid....
I use Ocean and Earth Premium 8', ankle, for 8' SUP. I had an FCS one before and the Velcro cuff failed. Using an arborist throw rope line for leash string, think it's similar to the Dyneema folks use, the strings before kept wearing out quickly
Ocean and Earth Premium (the ONE) + 2 dyneema cords (main 3mm + a 2mm a bit longer as a safety, + ends melted into the knot with a lighter).
I remove (cut) their built-in cord that can fail.
7' for boards up to 7'8" / 7'10"
I had no problem with the Creature of Leisure either, but the O&E seems to me stronger by design.
Had various failures with Da Kine, Channel Island (the hexagonal one), FCS...
And of course, I blunt the trailing edge of fins with a Donaldson trailing edge (half-round it)
I've been loving the starboard 9mm 8ft or 10ft ones. About as thick as any I've seen in the market and priced really well. They were on sale at my local today so I got another 2x just for safe keeping!
Balin Storm 10mm.
Not had one snap (yet).
Previously had a few O&E Ones but they seem to stretch more and have snapped a couple.
I had the Starboard thick one. The first time I took it into sizeable waves it got cut straight through resulting in a long swim back. I had the O&E premium one mentioned above last a lot of sessions. It took quite a lot of cuts thanks to the bit of steel, but snapped in December. Now I am trying an FCS leash
I use a waist leash - "home made" with either a 5/16" or an 8mm thick cord,
with two leash loops.
I have two other waist leashes from vendors - a LEASHLOK HAWAII
which is OK and a Crow Haley, which I think was better but which I lost. Still,
I like my home made one the best - that is the one I've been using for a few years now.
When I go back to an ankle leash, whoa...too much pull on my knee.
I think I need that thickness of the cord or more for the volume and weight of my SUPs.
Ocean and Erath one and premium 8'' or 9'', never broke one... Some other brands are good also but call it superstition i use only O&E.
I believe the secret is more to change them on regular basis even if visually in good shape. I use them 6 months max for big/medium waves and after that for flat or small waves.
Leashlok and Crow Haley waist leashes. Both good quality. The leashlok system allows simple replacement of parts if needed.
Good reminder to take a close look at my leashes and replace if needed.
Bob
As an old bugger, I endorse most of the comments.O&E and Creatures are both good.
read carefully the specs and go for a leash that is more than fit for purpose.in other words a big wave leash that's got enough length. Keep a close eye on the attaching cord which wears with time and can be the weakest link.
as other have posted - i always run two cords & also phase my leashes out over a season into my boards for smaller surf.
There's no worse feeling than getting tumbled out the back on a big day and feeling the tension on your ankle suddenly gone
Ocean and Earth premium one XT. Had a great run with these. Their ankle strap is now even more comfy too 
.
Just broke a dakine in 3/4ft surf this mane and got a swim for my troubles. Gunna give an FK 9' a try -a Sideways special so gotta be good right?
I find that the dakine big wave leashes hold just fine but I do replace them every year
