Thanks steevo, that's more and less in the ballpark of what I have gotten so far. Decent but I may be carrying an extra battery just in case (yep, I am a bit of a water rat/hardcore). I will also carry a separate battery pack for the LED lights ($1.99 from RadioShak). May even get a tricle charge solar panel for the battery not being used/possible bait tank. Although I think the bait can be keep in a mesh in the water, on the other hand, I preffer artificials and have had great results in learning to use the different kinds. It is about learning to use them and choosing the right one for the day and time (which is not written in stone at all, if anything the fish will tell you). Learning to use them is a bit more tricky, yet interesting.
To report back on my tests. When I connected the battery straight into the GPS/sounder it worked fine, I think the LEDs may be helping with the interference when turning the backlight on on the 178. I also learned that it is possible to actually turn the sounder portion off, thus save battery life/backlight time when cruising. Now, to plan next outing . . . thanks to all again.