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1997 Z276 MCM. I'm installing my new Humminbird Helix 5 GPS/Sonar DI today. The transducer is the issue. I searched everything on here about mounting it in the bilge but I need to specifically need to know if the engine bilge area is pure glass or is the bottom of that area a glass/wood/glass composition. The inside of my engine bay is gel coat finished. It's finished out like any other place on the hull that can be seen from the outside.
I'd prefer NOT to have the transducer hanging off the back for aesthetic reasons. I even cut the paddle wheel off cause I HATED the wire running up the transom.
I'm not worried about holes. I have full faith in 3M sealing them up for cable passage. Just don't like the look.
So, in summary, is the floor of the engine bay/bilge solid glass or is it sandwiched ?

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The floor of the engine bay is a false bottom. There is an air gap between the engine bay and the bottom of the hull. If you want to get to the hull bottom fairly easily try looking in the access hatch located under the cabin stairs. That is where the factory located the transducer for the depth finder on our boats.

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Thanks Steve. That's what I'm going to do. I just won't get a reading on plane but that's fine, the main reason for that graph is the GPS and Lakemaster charts. Thanks again

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Brian - I'm not certain that that portion of the hull is out of the water when on plane. Another albeit scary option is to cut a hole in the engine compartment to get to the outer hull. I have often thought about doing this so the bilge pump in the engine compartment is as low as possible. If you leave your Z in the water for any amount of time you will find out that the main, midship pump cannot remove all the water from the bilge, there is always a quite a few gallons in there.

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Steve, yep, I've discovered the "hidden gallon"! After this weekend, I've got to pull the gimbal ring to get it re machined and I may go ahead and pull and unused seacock and see how much of a gap there is between the inner and outer hulls. If there is an inch or more, I'm going to do that. Hole saw a place at the back to get a bilge pump in. I can't image that area staying damp is good for any wood in the stringer system. I'll let you know what I find.
I'm assuming we have the same boat ? We bought Chip and Terri's Z276 from this site. Good guy. He hated selling it but I got some awesome puppy dog eyes.
If there is anything you need as far as what it looks like or how does it work on my boat, let me know.
BTW, I just epoxied my transducer in the shower sump area. Built a small dam to get it more level. Let you know about the planing issue

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Graph is awesome. Ended up buying Lakemasters chip. Not as much info as the Navionics but Lakemasters has an option for highlighting any depth you want to stay away from and the same for any depth you do.
The DI worked just fine. The sonar did struggle on plane. Would tell me I was in 2 feet of water but Lakemasters said I was in 175'. Slow down a bit or trim it down a touch.