Hi blue robotics enthusiasts,
Here is a simple, efficient and economical method of making an attachment point on the umbilical cable of your favorite ROV. I use it for years without any problems and i think it’s now time to share it ! 
But rather than explaining it to you with a long boring text, I did a short video …
Nice video 
Given your use of the soldering iron, I’m assuming your string is nylon or some other thermoplastic, and you’re sealing it so it doesn’t come apart once ‘cut’?
Thank you !
yes, you’re perfectly right, i use a nylon lacing cord, which is commonly used to tie wires harness.
What is the black “sock” material called?
Generally, these expandable braided Cable Sleeve are made of rilsan ( Polyamide ) or PET