Question about HDS 7
 

At slow speeds (1-12 mph) my hds 7 shows both bait/fish and depth of water. When I get up on plane; it still gives accurate depth but screen is blank of bait/fish. I tried putting the "ping" speed up to maximum; but it doesn't make a difference.
The transducer is mounted on the transom and it is flush with the bottom. I was told if I lowered the transom just a hair; that might fix it.
Any suggestions?

Let me know what you find out. I have tried moving mine away from the motor more to see if it fixes the problem. Didn't work. I have the same issue. :confused:

Here's what I found out. It looks like it is normal for this to happen. I've been on friends boats with either the same model or similar model and they all lose sensitivity (for lack of a better term) in their fishfinding capabilities at higher speeds. Now this is taking for granted that we are talking about the transom mounted transducer that comes with the unit.
Mine still reads the depth fine, I just lose the "marks" for fish. When you compare the transom transducer, to a thru hull transducer, that's when you see a huge difference. My friends with the thru hull see marks at high speeds.
If I see ANYTHING except the white screen while I'm running (like the precursser of marks) you might want to double back and check that spot out at lower speeds.
I'm getting more comfortable with the unit every time out. I believe we just have to live with the issue or buy a thru hull (putting large hole in the bottom), or shoot through hull (but you lose the water temp. reading with this).
If you keep the boat in the slip, keep your transducer clean. If fouled, it will even lose the depth reading until you clean it.
Best of luck with your new electronics!
5th (Marty)

Thanks for the info. I was beginning to wonder if mine had a problem or not. I do have the transom transducer and keep the boat on the trailer. I had an older Garmin 320c fishfinder then went to a lowrance x96. After putting a new motor in my boat this spring, I went ahead and got a Gps/finder combo. I will keep and eye out for minor marks and swing back. Again thanks for the info. I'm hoping to get out this week and find some fish:D

An Airmar P-66 will probably do allot better, but check with your favorite marine electronics tech.

I see this is an older thread but wondering if you guys solved the problem of not seeing marks at speeds above 10 MPH.

Im deciding on an HDS 7 or 8 and not seeing marks at speed would definitely be a deal breaker for me.

The faster you go, the harder the down and side scan images are to see....

The HD sonar should work...

With the side and downscan some setting changes could help to get better clarity, but its really not designed for high speed....

If you want PM me and I can give ya a call to let you know about my experiences..

Oh and get the HD8 its worth it...