Hooks like the one shown in the image to the left can open and catch in your clothes. This can be DANGEROUS, especially in a capsize.
DO NOT USE THIS TYPE OF HOOK
See all Class Rules but especially:
Clearance between the span and the boom
The method of attachment of the mainsheet or mainsheet block(s) to the boom is optional (provided they cannot slip along the boom, and the maximum clearance between the span and the boom shall be not more than 100 mm, at any position along the boom). The position of the blocks or the length of boom strops shall not be adjusted while racing.
Personal buoyancy, bailer (tied in), paddle (tied in) etc.
4.2 (a) The helmsman shall wear a personal flotation device to the minimum standard ISO 12402-5 (Level 50) or equivalent. All fastening devices supplied by the manufacturer shall be used in the manner intended. A whistle shall be carried securely attached to the personal flotation device.
4.3 The following equipment shall be on board while racing:
(a) One or more bailers which shall be securely attached to the hull by a lanyard(s) or elastic cord(s). One bailer shall have a minimum capacity of one litre.
(b) A painter of a single piece of buoyant rope, not less than 5 mm diameter and not less than 8 m long securely fastened to the mast thwart or mast step. (see also 18.104.22.168).
(c) A paddle of wood and/or plastic, weighing not less than 200g, having corner radii of minimum 5 mm and a blade able to contain a rectangle of 200 mm x 130 mm shall be securely attached to the hull by a lanyard or elastic cord.