my dad just bout a new big lake boat and has an ancient old lowrance fish finder on it. my mom wants to get him a fishfinder/gps as a gift. shes left the choice of which model up to me.(im his teenage son) ive been doing my research and it looks like you cant go wrong with the hummingbird 700 models or the garmins. i did hear bad stuff about lowrance. any advice or help on making this choice would be great. my price range is up to 700. thank you.