A sad tale

[AdriftAtSea]

MaxiSwede—

It is far easier and faster to pull the lanyard on the snap shackle than it is to pull my rigging knife out and cut the line.    It is also far safer to release the snap shackle when I'm flailing around underwater than it is to futz around with a knife IMHO.

[maxiSwede]

Adrift -

I think indeed, we ARE talking of different animals... or more likely, my knowledge of english is'nt good enough. Could you post a pic of such a snap shackle, please? 
 

[maxiSwede]

Is it something like this you're advocatiing?

http://www.wichard-usa.com/Catalog/HR_Snap_Shackles.htm

Ouuch, I wouldn't even for a moment consider having my life depending on on e of those. They were widely used for jib sheets earlier in my sailing life and all I can say is - AVOID them anywhere! ...and on a harness/tether.... NO WAY, simple as that. They are not secure at all.

[AdriftAtSea]

MaxiSwede—

That is indeed what I am talking about.  However, I can assure you that modern snap shackles are quite secure and quite reliable.  Thousands of people are using that same beastie for safety tethers ATM, and they work quite well. Yes, you need to rinse them off and lube them occasionally, but they're quite safe if properly maintained.

[maxiSwede]

MaxiSwede—

It is far easier and faster to pull the lanyard on the snap shackle than it is to pull my rigging knife out and cut the line.    It is also far safer to release the snap shackle when I'm flailing around underwater than it is to futz around with a knife IMHO.

Adrift at Sea -

To each his own, I am not here to debate, but did you ever open one of those under a HEAVY load? I didn't, and I wouldn't bet my life on it, simple as that. The knife is the only instant-release mechanism I feel comfy with.... but again, to each his own. I would recommend everyone to -if at all possible - try your preferred solution out- in as close to 'the real thing' circumstances as possible and also; try to figure out the one system that would suit you, and your boat, the best. 

Happy sailing!