CD 30 Depth Finder Replacement

[Polly]

Hi Everyone,

I'm hoping to replace the depth finder on my CD 30 - I like the Raymarine i50 series, but they told me that their plastic transducer can't be mounted on an angle, and that it can't be used with an angled mounting block. Any suggestions for a quality depth finder with a transducer that can be mounted appropriately on an angled hull?

Thanks

[Jim Walsh]

Hi Everyone,

I'm hoping to replace the depth finder on my CD 30 - I like the Raymarine i50 series, but they told me that their plastic transducer can't be mounted on an angle, and that it can't be used with an angled mounting block. Any suggestions for a quality depth finder with a transducer that can be mounted appropriately on an angled hull?

Thanks

http://www.raymarine.com/view/?id=1479
I just took a quick look and they have a P79 transducer which works with a dead rise angle of up to 22 degrees. It would be best to call Raymarine Customer Support for an accurate response to a technical question regarding their components.
http://www.raymarine.com/display/?id=773

[Doug Gibson]

Check out the in-hull P79 transducer (I believe compatible with most if not all RayMarine instruments and fish finders/plotters).

I installed one on my CD36. You glue the mounting base to hull, fill with mineral oil and install transducer. Works great with my A-series fishfinder/plotter. Discounts for about $120.

[Astronomertoo]

Check out the in-hull P79 transducer (I believe compatible with most if not all RayMarine instruments and fish finders/plotters).

I installed one on my CD36. You glue the mounting base to hull, fill with mineral oil and install transducer. Works great with my A-series fishfinder/plotter. Discounts for about $120.

---------------
What is the maximum depth you have been able to read on the "shoot thru" hull xdcr?
I am not current on the newer devices. The reason I ask is that the transmit pulse (envelope) must travel thru (and be scattered and attenuated by) the fiberglass hull, then bounce off the bottom, back to the transducer, then finally to the receiver. The fiberglass hull with have a huge effect (absorption) on the signal strength on the ultrasonic audio signal. I am sure it will not be as sensitive as I used to look for coming back off the continental shelf drop offs, but what really is reliable now with the new devices of that type? Will it work out to more than 100 ft?
Thanks
Bob C

[Steve Laume]

I despised the huge fairing block that housed the transducer on Raven when I got her. When the old depth finder gave up the good fight, I bought a cheap Hummingbird. I took out the old transducer and block then carefully glassed in the hole and built up a level plug of epoxy on the inside of the boat. I then glued the puck to the inside and the thing doesn't seem to know the difference between a couple of inches of epoxy or water.

I don't think you have to mess around with a bunch of mineral oil these days.

I have one less hole in the boat and the hull is much fairer than it was before, Steve.

[Doug Gibson]

I have no problem with depths (and fish / bottom type imaging) to 200 feet with the transducer mounted inside the hull. Frequency is either 50 kHz or 200 kHz... goes right through a few mm of fiberglass. I believe my A-series transducer puts out 600 watts... plenty of power.

I agree with Steve that the mineral oil is not essential if you can glue the face of the transducer directly to the fiberglass (as long a you have a horizontal pad on the inside of the fiberglass). The P-79 transducer provides adjustable mounting angle, hence an air gap between transducer and fiberglass... so calls for mineral oil to ensure performance.

[Skipd]

When replacing the depth sounder in Keipr I opted for a Raymarine Unit and placed the stock non slant transducer as follows:
- used a 5" (if I recall correctly) piece of pvc pipe, cut about 3 or 4 inches long
- made a simple wood cap, sealed with epoxy, with a hole for mounting the transducer, which attached to the top of the tube
- the pvc tube was shaped a bit on one end and then caulked (used 5200) in the bilge about 6" aft of the ballast
- filled the tube with water (in case it leaked), attached the cap w/transducer. Empty the water in the fall, add in the spring, because of freezing.

This solution cost a few dollars and has worked fine for 4 years. The depth reading is about 3' aft of the keel leading edge.

Thanks