Humminbird - Interlink - GPS (need help)

[NTW]

I currently have a 998c SI on the console of my boat and am looking to add a 700 series combo to the bow and interlink between them. I have found a couple options and am looking for advice.

- 787c2 combo or 788ci combo

I've looked at the spec differences and think I understand everything except the GPS part. When I interlink the two, I want them both to use the external GPS at the back of the boat and share waypoints. The 787c2 says that it has 16 channel GPS and the 788ci states 50 channel GPS. Can I assume that they would both perform (chartplotting, lakemaster chip compatibility, etc.) the same when connected to interlink and using the external GPS?

What other items should I consider? I think I can live without the display pixels and preset buttons.

[hanson]

If I'm not mistaken 16 channel GPS vs 50 channel GPS is the GPS receiver (puck) itself. You can add a 50 channel to a unit that comes with the 16 channel.

Since you are planning to Interlink them and share the rear GPS puck (which I assume is a 50 channel), I wouldn't worry about what GPS puck comes with the unit you buy. They'll both be sharing your existing 50 channel GPS receiver.

My opinion is that you should have a separate GPS puck for your bow unit anyway. Wherever the transducer for that particular unit is located (bow = trolling motor), thats where the GPS puck should go as close as possible. If you have a 16' boat for example, if your bow unit is utilizing a rear GPS receiver, your accuracy is already 16' off already before you factor in the GPS accuracy.

Both your units will still share waypoints through the Interlink, but they will both have more accurate GPS data if you run a GPS receiver for each unit at each end of the boat.

Remember that each unit will require its own mapping chip (Lakemaster, Navionics, etc...). That data is not shared between the two units.

[reddog]

Save your money and dont buy the interlink. Buy the unit that will connect with an ethernet cable to your 998.

Interlink will be a thing of the past soon, especially if you dont own one now.

[NTW]

Save your money and dont buy the interlink. Buy the unit that will connect with an ethernet cable to your 998.

Interlink will be a thing of the past soon, especially if you dont own one now.

I don't think that is an option...my 998c si doesn't have the ethernet plug.

[Jason_Halfen]

The 998 has an ethernet port. It's the round port, right in the middle of the back of the unit. Doesn't look like the ethernet port on your computer....but it's there.

[NTW]

Thanks for sharing that with me. This is far more complicated than I had imagined. One other upgrade I want to make is to add a shoot thru transducer so that I can switch to it and get a normal sonar reading at higher speeds. I can't tell which equipment I need to buy for that either... I am not a fan of humminbird's site, probably just my lack of ability...

[Jason_Halfen]

I assume you're running a glass boat? A shoot-through-the-hull ducer is designed to work with glass. If you have tin, some guys will add a standard high speed transom transducer and raise their HDSI ducer up a couple of inches to protect it from junk in the water.

If you're running glass, here's what you need:

XP-9-20 (shoot through hull 2D transducer)

AS-SIDB-Y (Y cable to link HDSI transducer and 2D transducer)

For tin:

XNT-9-20 (transom mount 2D transducer)

AS-SIDB-Y (Y cable to link HDSI transducer and shoot through hull transducer)

I should note that I run a glass boat (Ranger 1860), I run a single HDSI transducer, and I have no trouble collecting SI, DI, and 2D data at my top speed of mid 40s. I have all the parts to run two transducers, but I've never felt compelled to do so.

[NTW]

Awesome, thanks Jason! I have a glass boat (champion 181) but do not get any sonar reading above 10 or so mph.

So I think I've settled on a plan then.

1)I am going to buy the used 787c2

2)Buy an interlink for that with the 998c si. (787 doesn't have ethernet)

2)Buy the XNT-9-20 & AS-SIDB-Y for the console unit.

3)Buy the new Lakemaster chip so I have one in each unit.

4)I am not going to install the second GPS antenna because it is 16 channel AND I installed the 50 channel for the other unit in the middle of the boat (like an [PoorWordUsage]). So they can share that one and I'll be about 9' off with every waypoint.

I hope this all works out. Thanks for helping me understand what is compatible!