Sam W. becareful on the units your looking at. You mentioned the HDS 5m. That is a gps only unit. Here is a quick breakdown:
HDS 5 (sonar/gps combo)
HDS 5m (gps only)
HDS 5x (sonar only)
So just double check your units your wanting. There will be a difference in prices also.

GoneCrappiefishing, for the networking that's a great thing to do. I have both HDS 7 & 8. Great combo especially the 8. Large screen and quick buttons which are awesome. As for networking, you can do both ethernet and N2K. If you do not plan on putting the external antenna and N2K sensors, then there is no use in spending $150 for the N2K network. N2K does share waypoints but its partial waypoint sharing and gps data. But since each HDS unit has it's own gps antenna and workings, then no need unless for the external antenna like i stated above.

Ethernet is a different story. Ethernet does not share gps data but you do have full waypoint sharing and sonar sharing. By "full" that means when you add, edit, delete, change names, move, etc. to a waypoint on one unit it will do the same for the other unit. You can also do this with one unit and when you connect and turn them one it automatically updates the other. That also includes importing waypoints onto one unit. It will transfer to the other. Example, i was renaming some points on mine the other night in the house at the computer desk, when i put the unit on the boat the next day and connected the two, it updated the other unit on the bow. N2K does not do that and thats why i put "partial". It will only place the waypoint but can not edit it from another unit.

Now for sonar networking sharing, It's great cause you dont get interference from another ducer being on. This is done via the ethernet network also. Bascially, if you have two transdcuers, TM and transom, you can share on both units. If your fishing with a partner and your on the TM, you can set the console unit to display what is being showed on the TM unit. The partner in the back will be seeing what your seeing, thus that leaves the transom ducer off and no inteference. Same thing with the transom ducer, you can have it show on the TM unit. With that, you are seeing what's behind you and not directly under the TM. I personally don't like the sonar sharing cause i want to see what's under me at that point and time. There are settings in the unit that can turn "off" the sonar networking.

For networking, N2K will be in the $150 +/- just to get started then goes up depending on what other sensors you add. This is all extra cables and T's for connections. For the ethernet it's only one cable that long enough to reach from unit to unit. You connect the 2 units directly to each other. That's about $40 for the 15' cable and a little more for the 25' cable. Of course it all depends on your boat size.

Now if you plan on getting the LSS-1 it will connect up to 3 HDS units and also serves as an ethernet hub. All units are connected to the box via ethernet cables. You can still share sonar and have full waypoint sharing but no gps capabilities thru it.

Lowrance Self-Service Support Here is a link to the "HDS system overvies" that explains somethings on networking.


Hopes this helps you out.