Knot meter has two transducers?

[drumbeater]

My old boat has two speed transducers in the bow. They are not in the thru hulls right now, the dummy plugs are in there.
One is an ST-1 and the other is an ST-5. What is the difference between the two?

 

[Ted]

My knot meter has two transducers

Who is the manufacturer of your instrument and transducers? They may be different.

 

[drumbeater]

I think Standard/Horizon. I found some info on the web once but I can't find it again.

 

[Merlin Clark]

Thought it might bbe on here but don't see it. You might want to bookmark it anyway: http://www.fujiyachts.net/manuals/