A top connector for a tether of a subsea buoy is disclosed. The connector has a support, a lever member movable about a pivot axis, and a chain stop mechanism mounted on the lever member to be situated below the pivot axis in use. The lever member is pivotably connected to the support via a flex joint arranged to bear a tensile load exerted by a top chain of the tether when engaged with the chain stop mechanism. The flex joint improves bending fatigue life of the top chain. A frame extends upwardly from the support to carry a sheave for the top chain. A pivotably connected lever member extends downwardly from the support. The lever member is pivotable relative to the support and the frame, allowing a compact arrangement that avoids the frame, the top chain or the sheave clashing with the shell of the buoy.