8600 series and HD

[rxkid2001]

If you get a 8600 series unit it says it has the HD side view built in. I've been told its a good idea to still get the sonar module, apparently gets better images. Is this the case?

[LWINCHESTER2]

It's hard to say and there are so many variables I can only be subjective at this point. I used the GT34 with the GCV20 and did a fairly lengthy post about it at that time. I'm not sure but the unit was either a 7610 or 1242 or may have been the Plus 93sv. Now I'm using a 8616 with the GT54 plugged directly in. I thought the GT34/GCV20 did better on sidevu using the mega frequency. Since then I've also used the GT34, GT50, GT51, GT52 also on the 8616 with no box. That was with an earlier verson of the software. I really didn't see a difference that I noticed on the GT34 not using the box.

Now I am going to go out on a limb. On a limb because there's nothing in the release notes about improvements in SideVu and I would have expected it to be noted. I'm using v15.0 and it sure seems to me that the SideVu has gotten better. Seeing fish at extended ranges against the background of the bottom seems noticeably better across the board. I posted a few images of the GT54 and GT50 and there was not a lot of effort put into fine tuning those images.
http://www.bbcboards.net/showthread....878&p=10140505

I still say that the GT34UHD does better than the GT54UHD on SideVu at 1120 kHz for looking at structure detail and that is with or without the box. There is a shallow water limitation on the UHD frequency. The box is in the garage and I've not seen anything that makes me think the box is better than the built-in on the 8616. The 455 kHz on the GT54 is spectacular for seeing fish even at extended ranges (over 100ft). That's not an option on the GT34.

[rxkid2001]

What is the shallow water limitation?

[LWINCHESTER2]

The best SideVu images that I have gotten from any Garmin transducer in shallow water. 30-40 ft.

http://www.bbcboards.net/showthread.php?t=899840