[DG] [DG] Transducer for CP 470

[striperstan]

I'm running a system (es128 and es97) with a networked CP470 and am looking for transducer options for my 27 ft catamaran.

I've been having good results with my M265 transducer, but the installation never lasts more than a year or two before the tank adhesion fails and it starts leaking. I've tried both 5200 and three different professional fiberglass installations. I'm thinking of going to a pocket mount. (PM265) rather than re-doing what I have yet again.

Boat is a ProKat 2660, and I believe there is enough space back aft by the battery shelf. I've got other transducers mounted there that work fine, so I know the water is clean enough. I bottom fish in water up to 1200 feet deep, so I'm also considering the CM111; but I don't know if I have room, or if the extra expense is going to make a big difference.

Looking for some real-world experience, as well as advice from the electronics gurus as I make my decision.

Thank you,
Stan

[Derek - Raymarine - Moderator]

HI striperstan,
Thank you for your enquiry.

The in-hull transducer installation is the better option if you can overcome the tank leaking issue, it would we worth calling Gemeco or Airmar direct for some tips on degreasing the hull before mounting the tank, to ensure a long term and reliable bond. Perhaps the hull is flexing a bit which is triggering failure of the bond between the tank and the hull?

Gemeco can be contacted at this link here for advice.

The alternative as you mentioned is the pocket mounted transducer version found here , we have virtually no installations of this type of transducer here in the UK, due to the hull types and market that prevail. The main issue with the pocket mount is the work required to modify the hull to create a recess into which the transducer will fit from the outside of the hull. This will need to be accurately formed and well glassed into the hull to avoid loss of hull integrity.

If mounted in the Keel, this will give the best performance from a beam point of view, whereas mounting off-centre, you will need to be certain the transducer beam does not impinge on the keel or hull fittings. If mounting in the keel, be aware of the fact that if the boat grounds this can damage the transducer face.

The actual performance from a sonar perspective is likely to be the same as for a conventional through hull transducer or an in-hull unit.

Regards
Derek

[striperstan]

Thanks, Derek...My fiberglass guy has also talked me out of the pocket mount.

I've engaged with Gemeco, and I think I'm going to grind out the fiberglass on the inside of the tank and seal it with 3M 5200. I am extremely happy with the performance of the m265 except for the leaking.

Another option someone suggested is to install a pair of B175 through-hull transducers; one L and one H. It is my understanding that this pair of transducers will not give the same level of performance I have currently have, and I will most likely be disappointed when bottom fishing in water up to 1200 feet deep. Is this an accurate perspective?

[striperstan]

Thank you , Derek. Several other folks agree with your assessment that the pocket mount may be too much work. I have engaged with Gemeco and some local fiberglass experts. I think my next step is to grind out the fiberglass on the inside of the tank (the install consists of fiberglassing both the inside and outside of the tank), properly cleaning and degreasing the tank and the inside of the hull, and sealing/bonding the inside edges with 3M 5200, leaving the fiberglass mounting on the outside of the tank. If that doesn't work, I may purchase a new tank and start over bonding and sealing with 3M 5200 or West SixTen.

Another alternative suggested to me is to use a pair of B175s (one L and one H) through hulls...but looking at the specs, I believe that I would be disappointed with the performance when compared to the M265. I really need to read the bottom well at depths up to 1200 to 1500 feet. Anyone have any additional thoughts?

[Derek - Raymarine - Moderator]

Hi Striperstan,

I think the PM265 is the better option, Airmar can give you chapter and verse about why it is better, but the size of the ceramics used in the 265 will be bigger than the 175s for a start off and performance, particularly resolution of the fish targets will always be better from a larger ceramic - size is important in this respect.

regards
Derek