- Hi: The B & G Network depth sounder and knotmeters each sell for about $500
with nylon through-hull fittings in the mail order catalogs (Defender, Post
Marine & JSI). Our local dealer Electronic Marine, Inc. quoted $492.50 each.
The bronze through hulls cost about $80 more apiece. The dealer said that
they usually install bronze fittings on wooden hulls and that the nylon
fittings are fine for fiberglass. WE have a 1978 vintage B & G Hornet
knotmeter with the nylon through hull & it has been fine. --Barry