The Spinlock XAS had the tightest grip in testing, but you can’t bleed the line.

A book could be written about the ways sailors have struggled with the bitter end of a rope. Many are the devices seamen have cobbled together to control and belay the whip ends of the lines aboard.

In Nelson’s day, there were clusters of bronze, wood, or iron belaying pins in pin rails along the deck and in fiferails (aka spiderbands) at the base of every mast. Pull a pin, and a line was instantly free. It was quick and easy, excellent in an emergency, but woe to the sailor who got it wrong. (Belaying pins had another less sociable use. No wonder Germans call them coffeinagels, which has a…