A question about knots... (figure 8 > bowline)

[redrover]

Hopefully only a sight hijack here, glad this came up.

Have suffered 2 yr old zip ties breaking, seems soon to me. But maybe the UV thing here (plastic does disintegrate) goes further than relatively limited sun exposure. (Out in the sun, buckets last at least 3 years.) So anyway, wanting to co the cave line attachment route now.

Is ‘cave line’ some specific cord? When tying cave line what knot? I’ve had several figure 8’s (my first knot of choice to say attach a cord to something) come undone underwater. Never had a problem on land (used to do a lot of specific knot for situation daily.)
I got some thin cord from a Marine store. Dry I would have used Parachute Cord but fear it’s too slippery. Have what I’d use for staking or a plumb bob and seems indestructible here. I keep hoping the stuff left all over the rock walls 20 years ago when house was being built will rot away, not looking like it happening soon but not so sure about that when water logged.

 

[The Chairman]

All of my reels have a rewoven figure eight on them. They retain a lot more of the line strength than a bowline.

For stopper knots, I use the grape knot, and these are especially good when I tie my regulator necklace.