Wesmar SS395 Installation & Operation Manual page 18

Avoid installing the seachest near other sounding
equipment. Down sounders should be behind the
seachest. Other sonars should be on the opposite
side of the keel.
Select a location 1/3 to 1/2 of the ship's overall
length back from the bow. On lighter boats where
the bow is likely to come out of the water at times,
moving the seachest closer to the half length is
recommended.
Athwart Vessel Location:
1. Installation through the keel is optimum,
center line of vessel roll.
2. Along side the keel and 1/2 in (13 mm)
up from the keel is a very good location, vessel
roll is minimal. The keel also adds strength to the
seachest as it protrudes through the hull. Fair the
seachest to the keel. Alongside the keel will help
keep debris from snagging.
3. If next to the keep is impossible, locate
the seachest within 40 in (1 meter) from the keel.
The bottom of the seachest must extend down to
1/2 in (33mm) up from the keel. Fair the seachest
for-and-aft but not to the hull. If faired to the hull,
bubbles will travel down the taper to the soundome.
To deflect debris a plate cut at a 45 degree angle
to the hull should be attached to the leading and
trailing edge of the fairing. The plate will deflect
debris and not catch on the seachest.
2.2.3 Seachest Specifications
The SS395, depending on the model, will have a 6
in soundome or an 8 in soundome. The size of the
soundome will determine the pipe and the flange
specifications. Use one of the following drawings
when fabricating the seachest at the boat yard.
Steel and wooden boats use steel. Aluminum boats
use aluminum. Fiberglass boats use fiberglass.
Fiberglass seachest with flange can be ordered
from WESMAR. (6 in part #62.04327.0 or 8 in
part #62.04329.0)
6-inch Seachest
1. Use 6-inch schedule 80 steel pipe
(5.761 Id nominal)
2. Length between minimum length (3.2.1)
and 40 in (1.2 m)
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