INSTALLATION TIPS FOR TRANSDUCERS
SAILBOATS:
The preferr e d positio n of the tran s d u c e r is where water is diverging arou n d the hull and is free
fro m turb ule nc e and eddies. This is generally in the forwar d one - third of the hull in front of
the keel and appr oxi m a t ely one foot off the centerline. Generally the knot meter tran s mi t t e r
can be mou n t e d on one side of the keel with the dep t h tran s d u c e r in a similar positio n on the
opp o site side of the keel. If due to access conside r a tio n s, it is necess a ry to locate the dept h
tran s d u c e r and the knot mete r tran s mi t t e r on the same side on a fore and aft line, be sure to
locate the dept h tran s d u c e r forwar d of the knot mete r tran s mi t t e r so that the turb ule n c e
create d by the pad dlew h e el does not interfere with the dep t h sens o r.
The dep t h tran s d u c e r sho uld be installed in a fairly flat area where the degree of angle does
not exceed 20 degree s (you can use fairing blocks to acco m plis h this). An altern a t e locatio n is
along side the keel two feet away and ahea d of amid s hi p s.
The thru hull fitting s require a 2 1 / 8" hole with a 30 degree flange. SR Mariner provide s a tool
(THT) that drills and flares this hole in one opera tio n. If this tool is not available locally
contact the factory and arrang e m e n t s can be made to rent one (the THT tool require s an 1 / 2"
drill moto r).
NOTE: The thru hull fitting should already have an o- ring installed.
INSTALLING THE TRANSDUCER
THRU HULL:
Choose the locatio n of the sens o r s and cut your holes for the thru hull fittings. File a notch
FACING FORWARD to seat the key way. The key way ensu r e s pro p e r orient a tio n of the senso r s
for use and / o r main te n a n c e. After pro pe r fit is secure d, place bed din g com p o u n d arou n d the
lip and body of the fitting where it will be in contac t with the hull. Insert the thru hull fitting
and tighte n the fitting nut by using a span n e r wrenc h or tap with a small woode n block agains t
the nut to provide a snug fit. DO NOT OVER TIGHTEN!
CEMENTED TO HULL:
If your prima ry impo r t a n c e is for shallow water monito ri ng, the tran s d u c e r may be ceme n t e d
to the hull there by elimina tin g a need for a hole thro u g h the hull. The position selecte d mu st
not have air voids, balsa fillers, etc… It is best to choose a locatio n and make a small putty
da m and fill it with water and put your tran s d u c e r in it to see if a stable dep t h is indicate d (the
boat sho uld be afloat and the tran s d u c e r face shoul d be wette d before inserti ng into pu d d le).
At this point back off on the gain until reading beco m e s uns ta ble to see how muc h reserve
gain is available. Comp a re this gain setting with the tran s d u c e r hung overboa r d; this will give
an appr oxi m a tio n of atte n u a tio n at the chose n location. If operatio n is suitable, clean the
surface of the tran s d u c e r with lacque r thin ne r to remove the anti - fouling paint. Clean the hull
to remove grease and mold release. The tran s d u c e r may now be ceme n t e d with epoxy or
fiberglas s resin (stir the epoxy slowly to avoid air bubble s). THERE SHOULD BE NO AIR
BUBBLES IN THE ADHESIVE BOND.
