Odd Sonar/GPS question

[Savage Brewer]

This may sound odd, but do any of you run separate units in your boat for Sonar/Stucture Scan and GPS Chartplotting?

Reason I ask, is I am looking at re doing my boats finders, I really need to add GPS / Chartplotting functionality.

So I am wondering if I put a pair of HDS in the back, one always running GPS, and the other is running depth and imaging, are there any problems or features I lose versus running on one unit?

Reason I ask is if I do a HDS-7 for sonar use and a HDS-5 for GPS I wind up with more usable space on screen and I save about $1000 over a 10" model. It also gives me the ability to have a backup unit in case one loses its mind.

So I am wondering if any of you chose to run multiple units instead of the split screens on one?

Thanks

[Superduty]

I am surprised more people don't do exactly what you are saying. Lots of cost saving and more screen space by buying two smaller screens. The main issue will be with battery power. The HDS units use a ton of juice. If you run multiple HDS all day you will need a group 31 for sure and might need to add a separate battery dedicated to your electronics.

[Old Dewjabber]

I do the exactly that. The main reason is I like the maps as the main screen to zoom in and out easy. I run sonar on the split with the gps, easy on off.

Other one I leave for DI/SI which is not on all the time! So far works good for me. Still playing with them as I'm fairly new with them.

I have said in the past that I wanted a separate GPS unit. Problem is now solved!

[speednut]

I was using a handheld GPS and picked up an Elite 5 DSI this year. I can't bring myself to take out or move the 103C, so I didn't mount the transducer on the Elite. I just use it for the GPS. Just got back from a week fishing and I really like the 2 screen setup. No more squinting to read the handheld, and I have full screen on each.

[S.D. Ice Angular]

I do exactly that also,

I run a HDS-5 for my sonar and an older LMS 337 for my maps. You don’t need a HDS quality to run maps. I have both wired into two different transducers on each side of the motor. I do turn off the transducer on the mapping unit when not using the sonar portion. I have them both on my dash and it works great. Superduty is dead on when it comes to battery life & dewjapper is dead on when it comes to the zoom feature also.

[Savage Brewer]

Thats good to hear, interesting that the HDS's really burn through batteries, is that the same with Himminbirds lineup?

Also are you seeing the smaller HDS's also consuming alot of power?

[Esox_Magnum]

I run a 5 and 7 on my boat, 5 on the dash 7 on the bow both run in split screen graph/gps however when I add the LSS to the system at some point I will add a dedicated unit for that. I'm also toying with the idea of adding my LX-7 on the dash for graph and running just gps on the 5 for the guy in the back....Guess battery life to me is a non issue since I charge the boat after every trip think I have a group 24 in mine...Plus I run the radio at all times and a car charger for cell's, go pro and I Pods...

[Superduty]

My new group 24 wouldn't start the motor after running livewells, two HDS units, and LSS-1 for a few hours on a hot day last summer. I replaced it with a group 31 and havn't had problems since. It might depend on your fishing habits and what type of outboard you have. The big direct injection motors take a lot of MCA to start. I keep my batteries charged with a newer onboard charger as well.

[Savage Brewer]

My Yamaha 40hp 4-stroke doesnt need much current to pull it over.

I also have a pair of group 27's up front wired in series for my 24v minnkota.

If i would wire the unit to my trolling motor batt, which one should I connect to? The one that shares the negative with the tolling motor?

[Esox_Magnum]

It is recomended to not hook up anything but the trolling motor to trolling motor batteries.... I run an old 115 merc don't take much to get it started....

[Superduty]

My Yamaha 40hp 4-stroke doesnt need much current to pull it over.

I also have a pair of group 27's up front wired in series for my 24v minnkota.

If i would wire the unit to my trolling motor batt, which one should I connect to? The one that shares the negative with the tolling motor?

This configuration will work in theory, but I would expect a LOT of interference when you step on the trolling motor power. It's also not good for your trolling motor to run off of 2 batteries that are not equally charged.

[Kyhl]

I don't think you are doing your calculations correctly.

Here are the actual screen sizes for 4:3 screens.

A 10" screen has an area of 48 square inches (8"x6")

A 7" screen has an area of 23.5 square inches (5.6"x4.2")

A 5" screen has an area of 12 square inches (4"x3")

So a 10 inch screen has more viewable area than a 7" plus a 5".

An 8" plus 7" would have 5 sq inches more viewable area over a 10 inch but I think that would be more expensive than a 10".

That said, there are advantages to having two screens, one for gps and one for imaging/sonar, even if they are smaller.

[CaptainMusky]

I think the determining factor of whether or not you "lose" anything by having multiple units would be if both units were equally equipped or not. You can buy a "mapping" only HDS which obviously would only allow you to have GPS and chartplotting. This would be fine for a dedicated unit, but if you ever had desires to move it around the boat or as a backup sonar unit you are stuck.

If you buy both units as sonar/gps models there are no disadvantages I can think of other than extra cost. If you choose you can buy one without a transducer to save a few bucks, but it may be worth it to have a spare.

[Savage Brewer]

my calculations are in pixels, not in inches.

The reason being that if you split into 3 modes, GPS, Sonar and Stucture Scan/DI/SI you wind up with viewable areas that are hard to work with.

An HDS8 and 10 both are 800H x 600V

Two HDS5's would give you 960H x 480V (480x480) so you have enough pixel space to make it usable.

To me a single display doesn't work well when trying to show 3 different things unless you step up to the new Gen2 Touch widescreen models, but that is expensive on its own.

Or if you go with an 5 and a 7 you wind up with 1120H x 480V.

I wish they made these units with an external 2nd display that could be run off the 1st unit without all of the cost. Seems dumb that they haven't done that already, all the second unit needs to be is an auxiliary display from the first one, so you can display more information, just like hooking up a 2nd monitor to a laptop.

Heck they should be able to sell a 2nd display 8" screen for under $600 but I assume that companies like Lowrance and Humminbird know that people will pay a premium for their high end gear, so why bother making something awesome and affordable.

[raymondk]

I mounted a ds5 and an elite 7 transducer on back of my boat the transducers are mounted no more then 4 inches a part there 7 is no interference at all I can run both at the same time .when I want to run something in the front I can grab one of them works out great for me.the elite 7 in regular sonar can use the same tranducer as the ds 5.

[PerchJerker]

I run two 5" screens just for mapping in my boat, one on the console and another on a rail mount by my kicker. I run an 8" screen for sonar / side scan / down scan.

They're networked together to share gps position, waypoints, nmea data, and transducer signals.

I think it's an ideal set-up, very easy to zoom in and out on the maps for navigation while running, very easy to see the contours while trolling, and very nice to have a back-up unit in case it's ever needed (I have never needed it but it sure adds some peace of mind knowing it's available if needed).