Echomap Plus 93sv + GT30 + GT8 (Y-Cable) Setup Questions

[TNBassMan10]

I have a 2016 Nitro Z-18. I recently made the switch to Garmin Echomaps. I have the new Echomap PLUS 93sv with G3 LakeVu. Up front I have the GT52 transducer. In the back, I have a GT30 transducer y-cabled in with a GT8 transducer. Today was my first test run. I lost depth reading at speeds 45-50 mph. My boat will do 62-64 mph. I'd like to get the depth on plane all the way through if possible but at least closer to 60 mph would be nice. I had the GT8 professionally installed. It's mounted correctedly in-hull. Are there any settings that will boost the performance of the GT8 so it will pick-up at higher speeds (such as increasing the gain or reducing the cone degrees)? Would swapping to a GT15 work better than a GT8--just in terms of keeping depth reading at high speed?

I don't care about performance of the 2D sonar as far as finding fish. I have the GT30 for that. I simply care about keeping a depth reading on plane while running. Did I waste money buying the y-cable and GT8?

Any help would be nice.

[fishin couillon]

It can be done by any professional but the other if it's not in that sweet spot it wont read at high speed.....you need that Y-cable so it wasnt a waste of money......with that said I have the GT15/GT30 setup in my boat. I do get readings up to at least 60 but it gets sketchy after that and if the water is choppy it comes and goes......i have not tried the GT8 so I couldn't say if that's the issue or not but it does have to be in that sweet spot.....did the installer test on the water before gluing down? Only thing I could think of is to get another ducer or take the existing one up and start testing it out in different places to figure out what that sweet spot is.

[TNBassMan10]

I dont know any pros in my area that would take the time to take a boat out on the lake multiple times to get the "sweet spot." I've seen where the GT8 is 250W and the GT15 is 600W. Would that make a difference on getting the bottom on plane?

[fishin couillon]

I understand but if you have someone installing something for you and they think it will work then thats a chance you take.....now if they removed an existing ducer and installed in the exact same spot, i could understand cause thats where the factory placed it.....thats just my opinion......i did the same on my old boat, removed factory place ducer and install new in same spot and it didnt read past 40 mph......i left it alone and used it like that.....

The GT8 comes with a "ring" that gets glued down and ducer sits inside the ring; IF the ducer is not glued down inside the ring and can be removed, maybe you can try it out in other places and do some testing to see which place is the best.....

As for the GT15, i went with it cause the existing low power lowrance ducer i was using gave shitty readings thru the hull but it worked up close to 70 mph.....i left it in place and put the GT15 right next to it and get better readings thru the hull and can get readings close to 70.....since the lowrance worked at those speeds, i would guess that the GT8 would also.....

In the end, if where the ducer is glued and that part is not making constant contact with the water past your indicated speed, you will not get a reading.......

I know i'm not answering your question but in the end it comes down to placement pretty much all the time....

[Todd Driscoll]

I dont know any pros in my area that would take the time to take a boat out on the lake multiple times to get the "sweet spot." I've seen where the GT8 is 250W and the GT15 is 600W. Would that make a difference on getting the bottom on plane?

The GT8 is not the issue. When mounted well in the right area, GT8 has no issues reading bottom at high speeds approaching 70 MPH.

[TNBassMan10]

It is place in the factory spot in a Nitro Z-18 2016 model.

[fishin couillon]

Did the previous unit give you readings up to 60 mph??

[TNBassMan10]

there wasn't one installed in the hull originally (I just got the boat)

[TNBassMan10]

Just to fill you guys in, I did find a way to make my transducer work. I'll need to experiment more but I didn't have the time today. By turning up my gain to "Auto High" and reducing the cone from CHIRP to the smallest setting (19 degrees I think) I was able to read depth at speed all the way up to my max top speed of 64 mph. Just food for thought.

[fishin couillon]

Good suggestion and glad you got it to work.

[Outofsightpdr]

I had the same problem. Garmin techs told me to run split screen with mapping and 2d. When I do that it works great at high speeds . If I run without 2d and straight mapping it uses the gt30 for depth and loses bottom at 30mph .

[Outofsightpdr]

I also have 2 9’s on my console. I had garming mail me a adaptor so could plug the gt8 in one machine and gt30 in the other. Didn’t use the y cable .