Those I finders are also really good if you do other outdoors activities. They have great maps for contours and road maps with forest rec roads etc and many other helpful features. I think that the Marine map is the most expensive and the other chips aren't as bad. The price for the marine chip isn't so bad if you consider what it used to cost to get all the maps from around Van Island. You used to have to purchase a chip for each area and the cost was brutal, now they are all in one chip. No doubt, this unit with the chip is one of the best investments to improve my fishing than any other gadget I have purchased in a long time. It made me see the light. <img src=icon_smile_big.gif border=0 align=middle>