I'm looking for a portable fish finder that I can attach to my grandfather's aluminum john boat when I go fishing at his lake.  As far as a price range goes, I'm trying to stay under $250.  Does anyone have a suggestion?  Thanks.

Before I got my Sea Eagle I used to rent aluminum jon boats at my local lakes and I came up with a way to use a fishfinder that should work well for you.  Get a 7"x7" wooden square (something like a floor tile or just a square of plywood), then mount your depthfinder to the square; take the transducer and mount it to the bottom of your trolling motor (most depthfinders like lowrance and humminbird make trolling motor-specific transducers you can get for $50-$70) and connect the power leads to your trolling motor battery and you are good to go.  You might have some wires hanging around so you can zip tie them to the trolling motor shaft.

That's true...I can always connect the power leads to the trolling motor battery and just use a regular fish finder and make it portable the way you described.  I've never owned a fish finder before though so I don't know a whole lot about them.  What is generally considered a good one in my price range?  Like I was saying I would like to stay under $250 with anything closer to $150 being great.

I would reccomend a Lowrance X96 in your price range.  It will show you everything you need especially in a private pond.  If you were fishing large lakes and needed GPS it would be a different story but for what you need the X96 would be great.  I have one on my Sea Eagle and it rocks.

For what you want, A Hummingbird piranha or bottomline will work fine...I have a piranha on the console of my aluminum boat that works great for what it is used for. I would not spend more than $100 ....Check out Basspro.com they have several in that range and some were onsale not to long ago.

I had a Pirranha MAX20 and it was alright but I upgraded because I couldn't ever see baitfish schools with any reliability.  The Lowrance is much better at showing baitfish and even Thermoclines.

I have a Bottomline fishin' buddy 4200 It works really well.

That Fishin Buddy looks to be just what I need in that it has self contained batteries and clamps right onto the boat.  It worries me a little though because I read the reviews on it on Cabela's website and most guys were saying that it eats through 3 D batteries in only a few hours.  They were also saying that the unit is a little flimsy and requires some extra clamping to keep it in place.  Are any of these similar to your experience with the unit?

I actually found that the reviews for the older models 1101 and 2202 were much better.  They use AA batteries and are less expensive.   :-?

You can make any fishfinder portable.

And buying batteys can make you broke plus the inconvince.

Get a 12 volt battery for Safefty. The ones that are on the wall for power failures. Available at industrail supply outlets. I just talked to the right maintance man at work.

They can be charged with a power point or trickle charger.

If you are in icefishing area the portable ice fishing flasher use the same battery my buudy bought his replacement battery from BPS.

Get a piece of 1x3 and bolt the tranducer to and a c clamp to attach to boat.

Garnet

I really like my piranha max portable.  Granted it is not the best unit, but works really well in shallow water.  I got mine for 100 bucks, so it is well under your range.  But seriously just look at the manufactures portable offerings, they will meet your needs great.  Lowrance makes a great one too.

I get about 15-20 hours on 8 AAs with my humminbird.

That Fishin Buddy looks to be just what I need in that it has self contained batteries and clamps right onto the boat.  It worries me a little though because I read the reviews on it on Cabela's website and most guys were saying that it eats through 3 D batteries in only a few hours.  They were also saying that the unit is a little flimsy and requires some extra clamping to keep it in place.  Are any of these similar to your experience with the unit?

I actually found that the reviews for the older models 1101 and 2202 were much better.  They use AA batteries and are less expensive.   :-?

I had the older fishin' buddy II and the bracket was much better than the one that came with the 4200. After using the 4200 for a few times, I got it xmas 2006, I do not have any problem with it. I only use it when I get to where I want to fish and then I only use the electric motor to move the boat. The older or new one would not hold up under outboard power. I have read the reviews about battery life as well. I have found them to be untrue. The fishin' buddy II easily lasted a whole season with 2 sets of three "C" batteries. Even with a week long trip to Canada where it was on 8 hours a day for 6 days. The rest of the year it was on maybe 20 times for 4 hours each.  I have used The new 4200 a few times since I got it a total of 8 hours and the batteries, 3 "D", still show full strength. This season will show more. You can easily get a 12v to 4.5v adapter at radio shack to power of a cigarette lighter. "D" batteries are cheap though.

That is very good to know.  The 4200 looks like it has the most features out of all the Fishin Buddies but all the bad reviews on Bass Pro Shop scared me off a bit.  

Ram makes a mount for the fishin' buddy fish finders I may look into one.

http://www.ram-mount.com/ramwebcompthumb/ram1051.JPG