Help!__Need info on 1979 Mako 25 hull design

[SoCal-Scott]

Curious... Looking at in-hull transducers (that sound through fiberglass) to avoid cutting large holes in the hull if possible. This would be a M265 transducer from Airmar that can sound through up to 1" of fiberglass.

Did the 25 in 1979 have wood coring (or any kind of composite coring) in the hull? The area I'm considering is the small compartment in front of where the original fish box was in the transom (mine has been removed and converted to I/O). So... it's about 4 feet or so in from the back of the boat down in and around the V.

Hoping somebody here with a 25 has cut into the hull toward the rear of the boat and knows for certain.

Thanks! Scott

[bigbender]

my 79 25 is solid glass.

[thejeepguy87]

I cut into mine about 1' forward of the transom to install the drain plug. It was 3/4" solid glass.

I can tell you that most boat builders lay solid glass in the bottom of the boats. Sailboats sometimes have core there, but most do not.

[mrdelgado]

Mine was around 3/4" too []

[Sailor]

3/4-1" depending on location (glass overlaps at keel)....BUT the real question is why aren't you doing a thru hull transducer? Make the cut and go fishing. You will be fine. [][8D]

[SoCal-Scott]

Thank all of you guys for the quick feedback, really appreciate it. This is a great community.

@Sailor

Well... this is a complicated question. I was originally going to use the Airmar B265 with a fairing block because it's dual channel chirp and more cost effective. Then I received it and it is enormous... when I talked to Airmar after the fact, they told me the info on their website is outdated and these B265 (or similar) should really only be used on boats 30ft and up. This thing is so huge and with the fairing block it's going to disrupt a ton of water in front of my prop and I'm worried about the transducer doing three things... cavitating the prop, changing the boat's attitude/handling and I would have to stick the trailer landing perfect every single time or it would hit the bunks and probably snap it off or seriously damage it.

My backup plan was then to go to the through-hull flush mount B175 units (one for low, one for high) but for my electronics I went with two NSS9 EVO3 Simrad units... and the B175L transducer won't work with any Navico products (Simrad, Lowrance, B&G). So then I would only have a high frequency B175H and just *cross my fingers* that Navico comes up with a software patch for the $1,000 currently useless B175L... no thanks.

So.... this started steering me toward the M265... which is basically the same Low/High or Low/Medium chirp unit that is in the B265 but just an "in hull" version as opposed to through hull. I've done a lot of research and people love them -- say they can't discern a difference between the in-hull vs through-hull. Same great picture, no holes, no trailering concerns, no water disruption

[Sailor]

I get the fairing block issue. I just had mine cut out and the hole glassed up, but I'm a ways out from replace all my electronics. How deep are you fishing?

[SoCal-Scott]

quote:

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Originally posted by Sailor


I get the fairing block issue. I just had mine cut out and the hole glassed up, but I'm a ways out from replace all my electronics. How deep are you fishing?

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Sailor... we fish in Southern CA, off the coast of Newport Beach... we have Catalina Island which is 26 miles off shore... so we fish the coast here, and the around the island at Catalina... and the channel between the coast and Catalina... the coastal waters range from 50-700ft and the deepest point of the channel is about 2600ft or so.

[cgmiller]

if you can send back the giant transducer, get a low profile tilted element unit. I installed one in my Grady and it worked great. The boat had a transom mount unit that always fouled. Had good luck with the tilted element one. We once had a shoot thru on the 17 but you have to make sure you sand the inside of the hull smooth and use epoxy to glue it down.