' bearings lubricated so that friction is at a minimum, 
and getting the BT down below the ship’s screw wash 
as soon as possible. With practice, it is possible to 
raise the BT slightly after the 30 seconds of towing 
at the surface is completed, skip it off the crest of 
a wave so that it swings well forward, and then 
lower it rapidly while it is still forward of the boom. 
This reduces the backward speed of the BT relative 
to the water and enables it to sink deeper before 
it is influenced by the water churned up by the ship’s 
screws. ; 
When the ship is making more than 12 or 14 knots, 
there is enough drag on the wire to ensure that it 
will not slacken. At lower speeds, the wire may be- 
come slack between the winch and the towing block 
when the ship rolls. This slackness may cause back- 
( lash on the winch drum or a kink at the towing block. 
The operator should provide himself with a stick about 
15 inches long to be used like an idler pulley on a 
_ slack belt to keep the wire taut. Do not touch the wire 
with the hands. 
STOP AT THE PROPER DEPTH 
When the counter indicates that the proper length of 
wire has been paid out, or when the last layer of 
wire on the drum has been reached, ease the hand 
lever to the brake position. Avoid a sudden jerk 
which might part the wire. The BT will now swim 
back ‘up near the surface far astern. Check to see 
that the wire leads back properly for hauling in. 
If it does not lead from the towing block in a line 
perpendicular to the winch drum, adjust the boom 
guys until it does. 
