On our St. Francis, the jacklines are run from very substantial padeyes (with rather large backing plates), just outside of the cockpit
combing up to a couple more attached to the crossbeam a few feet from the anchor
I can hook up while still in the cockpit
(where there are other attachment points) and get to all the necessaries, while my tether's length is such that I'll still stay on deck if I should loose my footing or get thrown. The only way I can go off the boat is over the bow. When up there, and conditions are rough, I'm on my hands and knees, anyway!