You might want to look here
http://www.setsail.com/c_central/techtalk/harness.html when thinking
about "biners" for the boat side of the harness. Experience in the 98
Sydney-Hobart showed that drowning can occur if the harness can not be
released by the wearer. I use a snap shacle on the harness side and a
biner on the boat side of my tether, but suspect there are better
set-ups.

-- Tom.