This would be a great product --- if the battery would last as stated in the manual. In my unit it lasted about 8 hours, not the approximately 500 hours.
The unit works well when working, though is VERY prone to failure. Even when completely dried off, the battery stays on and you end up having to buy another unit. If the unit gets banged against any hard surface, it's pretty much dead. The battery in the RF45 DOES NOT LAST 400Hrs. This is VERY misleading!!!!!! Of any I've purchased, the greatest length of time of use was maybe 4hrs. Hummingbird really needs to improve the design and make it more sturdy with a replaceable battery.
Humminbird® SmartCast RF45 Programmable Remote Son
Date:September 11, 2009
I've used this with the wrist watch display for 3 years with no problem. I've only had to change the battery in the watch once in all of this time. I've used it hours at a time and it never stops working. It tells me the surface water temp, shows me underwater structure and depth, and let's me know when there are fish around. In face I get a beep that signifies fish and gives me a rough idea the fish size. It don't do well with showing fish that are right on the bottom, though but that's okay. Using this unit has increased my fishing productivity enormously and I won't go fishing without it. This is a great product for bank fisherman like myself. I don't know why all of these other folks are having problems but that isn't my experience at all. The battery in the sonar unit will run down eventually but that is expected. Like I said I've used this a lot for three years and the battery is still good and the unit still works. A word of warning: keep this unit away from moisture or it will activate and use the battery and run it down.