I have the basic Hummingbird 100 on my sled and it works awesome, in the sun or overcast. Cost about $119.00. I can see fish going under my boat! I use my sled for both river and lakes so I didn't need a fish finder that went down to 600 feet. Range is 120 feet. It also has a duel beam transducer so you want to change the width of the area you want to see.