114 NICHOLLS'S SEAMANSHIP AND NAUTICAL KNOWLEDGE
40. What is done to guard against the edges of the' planking being
caught by the edges of the ship's plating when a boat is being
lowered?
The overhang of davits must be such as will admit when the vessel
is upright of a minimum clearance in lowering of 1 foot between the
ship's side and that of the boat. When the ship is fitted with a heavy
"rubber" or "belting" the clearance must not be less than 6 inches.
"Filling pieces" of curved form on the outside are also fitted to the
boat underneath the landing edges of the planking for about one-third
of her length amidships. These extend from the bilge to the gunwale,
and are a further safeguard.
The men in the boat would also assist in keeping her clear of the
ship's side.
il. Describe the sea anchor of a life-boat?
It consists of a bag made of good quality canvas formed in the
shape of a cone. The mouth of the bag has a diameter of betweeo
2 feet and 2 feet 6 inches, and is kept open by being sewn round a gal-
vanised iron or wooden ring. A double bridle is spliced round this'
ring in four places, eyelet holes at equal distances apart being made
in the canvas for this purpose. To the bights of this bridle 15 to 20
fathoms of 2|-~inch rope are secured to act as a cable. A small opening
is left at the point of the sea anchor through which some water escapes
as the boat slowly drives to leeward. A tripping line of light stuff is
spliced into a becket also at the point of the sea anchor for the purpose
of hauling it in. See figure 8, page 119.