I was in a large Marine supply store looking at Fish Finders. The fellow who was helping me steered me away from the $100 - $150 ones saying that they were really made for fresh water and would not work as well in the salt (eg a Garmin 140). He was indicating that my money would be better spent on a $260.00 Garmin that was designed to work in the salt water. What do you think? I would rather not spend the extra $100 if I don't need to, but on the other hand I do intend to use it in both fresh and salt water, both as a depth finder and a fish finder. Comments?