ive got a little hawk eye f33p (dont laugh
) fish finder.. im not looking to get rid of it but one could be an option. the one i have is small and portable. its got a ghetto screen tho you know, with the little fish that occasionally pops up.. i basically use it for depth and structure, tho i have been able to find bait and whatnot with it. anywho i made a pvc thing to mount it and the transducer on my yak but can take it out and i take it everywhere my yak my freinds boat float tube surfboard lakes i even threw it out off the cattle boat once just for fun.. and at about 50 bucks it wont break my heart when it falls overboard.. might not be what you need for lj but it works fine for me in the bays and harbors.
