Greenhorn question, but as they say....the shoe fits, so here goes...

Looking to add a depth-finder to my 13' dory -
Marine-grade battery or does it really matter?
Is that all I need, a battery and the electronic device? or do I need any type of other electrical/adapter etc??


Thanks in advance!

The simplest solution would be the depth finder of your choice, then pick up one of these 12 Volt DC 7mah batteries.
Lithonia Lighting 12-Volt 7mAH Replacement Battery-ELB 1270A R3 at The Home Depot (http://www.homedepot.com/p/Lithonia-Lighting-12-Volt-7mAH-Replacement-Battery-ELB-1270A-R3/202942483#.UcHF3-Bq50g)

And one of these float chargers to re-charge the battery after a day on the water.
Automatic Battery Charger - 12V (http://www.harborfreight.com/automatic-battery-float-charger-42292.html)

This way you don't have to lug around a heavy car battery. Just place the small battery in a plastic container like Tupperware, punch a hole in the side and run your fused positive and negative wires from the depth finder to the terminals on the battery.

in my opinion, if you can afford it, get a nice gps/sounder. even on a 13 fter it is a great tool. For $700 you can get the garmin 546S. you may not need the map for navigation but it is a great tool for locating structure & storing your hotspots as waypoints. use the map to put you near structure, use the sounder to see whats down there. you can probably get a cheap sounder for a couple hundred, but spend a few hundy more and you are styin'.

dunno.... on my kayak I used an eagle cuda 350 wired to 2 lantern batteries in a waterproof box. worked great. GPS/FF, batteries lasted a surprisingly long time.

The simplest solution...

Sounds simple enough, thanks!

How long should a fully charged battery last?


zacs, saw 2 on Amazon, 1 w/transducer 1 w/o transducer? I'm not an electronics guy,...which direction am I going in?

Thanks ~

you are definitely going to need one W/transducer.

by the way, i was just throwing that unit out there because I know it would fit the bill. there are other options from other manufacturers, and you may be able to find something in the $5-600 range and sacrifice some not needed bells and whistles. But you WILL need a transducer, and you should try to find a unit that has an internal GPS antenna so you don't need to find somewhere to mount an external antenna, and also one lest wire snaking around.

A small GPS/depth finder will draw about 3 amps +/-, if you get a 100 Amp hour battery in theory you could go 30 or so hours BUT you NEVER want to discharge a batter like that , you really don't want to go below 50% capacity so realistically you are looking at about 15 hours give or take. I would charge it up overnight after each use and you should be fine.