Factory installed depth finder

[Dave's ZT260]

My depth finder has never worked at speed from day one. It’s a through hull model and over 30mph it's useless. Has any one else had this problem? I have a stepped hull, but this is ridiculous. Maybe Kip has an idea.

[BOB'S 283]

mine works everywhere but the lake i do most of my boating on. i dont give it much thought because i figure by the time the dept sounder registers (at speed) that the back of the boat is in shallow water , the bow will have already hit something. seriously , it sounds like you're getting air under the boat as speed goes up . may need to remount sender to an area that has water under it all the time . you might be in trouble there my friend.if its parts failure, humminbird offered to replace my whole unit for $50.00

[Dave's ZT260]

It’s the Lowrance 3500 depth finder from checkmate. I just want to know general depths in certain areas. Since I rarely cruise below 55mph it very difficult to judge. Any one else have this model with the through hull transducer?

[vinny p.]

I have the same unit. It works reasonably well at speed. I am not going to say that it works all the time, but for the most part I don't have a problem.

[Dave's ZT260]

Vinny,

Do you have a stepped hull?

[vinny p.]

Well, it is not what I would consider to be a stepped hull. It doesn't look like a 42 Cigarette. But, there is a small cut-out just in front of the drive that some may considered a step. It does not go completely across the bottom.

[conv240]

I would say the operation of your depth finder is normal . As speed increases , by the time the signal from the transducer beams off the bottom and back to the transducer , the boat has already passed tha spot and gives you a false reading . They seam to work up to a certain speed . This has been my experience with all the fish finders and depth fiders I have had .

[Dave's ZT260]

Vinny, I think your referring to the transom notch. Therefore your hull is probably not stepped. My step is very pronounced and a good 8' forward of the transom and all the way across the bottom.

I have had depth finders that worked at high speed so I don't buy into the speed being the issue. I do however think the step is creating air pockets that confuse the sensor. That being said I don't think I can do much about it. If the senor was mounted forward of the step by the factory it should work better. To late now...

[vinny p.]

Dave,

I didn't know that the ZT260 had a full step. You learn something everyday I guess.
I would imagine that is your problem. You must be aireating that section of the hull.

[BOB'S 283]

dave , guessing you're s.o.l. . guessing you have more air under yours than most of us . might have to get one of those clunky transom mounts to find solid water

[Dave's ZT260]

I spoke to Kip, he is looking into it for me.

[CHECKMATE ZT 280]

Dave i have the same factory depth finder you have on my ZT 280 and it does not work at high speeds.

[Dave's ZT260]

Mine stops working at 35mph. What speed are you at?

[CHECKMATE ZT 280]

Dave works to about 30 to 35 mph then it starts to flash the numbers. Your engine looks really hot.Do you have any pictures of the rest of your boat? Robin

[BUKKAKIBLASTER]

My 97 280ZT also starts flashing about 35 mph & i agree- NICE engine Dave. http://checkmate-boats.com/6/ws/,s,8626072361/Graemlins/thumb.gif

[Dave's ZT260]

Seems like all our depth finders suck...Oh well.

The rest of the boat is basically stock. I'll put some pictures up soon. Maybe I'll get a mid air shot.