298 Bulletin, Scripps Institution of Oceanography 
handles the mooring wire, (2) a snatch block with manila tag line running to a 
powered gypsy head, and (3) a 1-ton chain fall. This arrangement provides the 
necessary versatility for handling the various pennants, the anchor, the floats, 
and similar gear. 
Work PLatTFroRM 
An overside work platform adjacent to the davit, and preferably flush with the 
main deck, is required for attaching elements to the wire and for handling the 
heavier weights over the side. The details will vary from ship to ship, but the 
platform should be of reasonable proportions and, when in use, rigidly supported. 
If it is to be used frequently, it should be designed so as to form part of the gun- 
wale when not in use, and either to swing out or to drop down when in use. This 
provides a clear, deck-level access to the platform when in the working position. 
SKIFF-RETRIEVING RAMP 
A skiff-retrieving ramp designed to permit the vessel to bring skiffs on board for 
servicing is very useful. Previous experience has shown that servicing an instru- 
ment skiff from a small work boat is a difficult and time-consuming procedure. A 
skiff-retrieving ramp built at Scripps was approximately 26 feet long, 4 feet wide, 
and slightly cradled to accept the keel of the skiff. Rails designed to prevent the 
skiffs from falling out of the ramp in the event of sudden yawing were added. The 
ramp was fabricated of standard 2- and 3-inch pipe, and was attached to the stern 
of the vessel by a heavy-duty ball-type trailer hitch. Two outriggers projected 
over the stern, one on each side of and adjacent to the ramp, to support and re- 
trieve the ramp. Under way, the ramp was carried in a horizontal position. In use, 
the outer end was lowered to the water by means of cables from the outriggers. 
The inboard ends of the cables were led directly to powered gypsy heads. 
NAVIGATIONAL AND ACCESSORY EQUIPMENT 
The installing and servicing vessel will usually need to know its position within 
very close limits, and therefore it should be provided with all reasonable aids to 
navigation. When trying to locate a small skiff in the open ocean, a radar is essen- 
tial. An echo sounder, Edo AN/UQN-13 or equivalent, is used to measure the 
depth and, in conjunction with the bottom-detecting device, to hear the impact of 
the mooring on the bottom. A take-off from the earphone jack on the echo sounder 
may be led back to an amplifier on deck and then to a loud-speaker near the work 
area, thus enabling the mooring crew to hear the signal on bottom contact. 
Mooring TECHNIQUES 
PREPARATION FOR LAYING THE MOORING 
Assuming that the vessel is in the area of interest with all gear on board, prepara- 
tions for laying the mooring consist mainly of assembling the various components 
to be used in the work area on the fantail (or other area, depending on the vessel 
layout). The wire rope and the nylon pennants are rigged ahead of time. One 
limiting factor is the time required to spool the mooring wire onto the winch if 
this has not already been done. 
