I used to use one when I use to float tube every weekend. But now I own my boat so don't need to anymore. But anyway they are great for the price and I use to catch a lot of fish with it. When you mark fish I could actually drop my worm down there and catch fish up to 7Lbs. But also caught fish on spoons and everything else when I metered fish. The only thing bad is they don't have (compared to what I am using now) that good of diplay and the graphics don't show you that great of detail. But for tubing they are well worth the price. They are compact and run on a few batteries which is very nice. The batteries would last quite a while but I always had spares just in case because like Don says they act screwy when the batteries do run low.Hope this helps.