tether

First off, I just joined this forum, but I've been reading and learning from it for quite a while, so I'd like to thank everyone who posts here. I'm going to start doing long-distance races, and am trying to figure out which tether would be best for me. I already have a Spinlock Deckvest, so...

Does anyone know if anyone makes a non-inflatable life vest that also works as a harness? I.e., it had D-Rings to attach a tether.