Depth transducer placement

[Fastdoc98]

Just ordered a shoot-thru depth transducer for my Lowrance nav unit that came with the boat and I'm wondering about placement.  My understanding is that it can be epoxied to the inside of the hull just forward of the mast in the storage compartment there?  My Eclipse has the battery in a box just forward of the mast but there's still plenty of space to mount the puck there if that part of the hull is solid glass.  If not, does it need to go further aft on either side of the keel or centerline but way aft?

[slode]

Mine is mounted right up against the forward wall of that storage compartment, dead center.  Just get your offsets set correctly.

[Fastdoc98]

Thanks for the info slode.  What do you mean by the 'offsets'?

[slode]

Most depth finders have programable offsets to account for placement of the transducer that is not right on the waterline. If your transducer is 1' below the waterline you'll want to set it -1' to account for that.  Or you can set it to measure from bottom of your keel.

[Fastdoc98]

Ah, makes sense now.  I would think keel bottom would be the most practical in terms of grounding/bottoming

[slode]

Maybe, but consider your rudder drafts deeper than the keel, and with the centerboard down you have an extra few feet.

I set mine at the waterline, knowing that I draft 5'2" with board down, about 2'5" with board up and rudder down, and 1'6" with both up.  For gunkholing in the backwaters this has all come into consideration and kept me from doing any damage.  You can add these depths to your keel draft, but I just find it easier to know how deep the water actually is in any spot.