I used to have one of those. I had made mine from and old weight that had been used to counter balance a window. I had a squirrel y depth finder on my first sailboat that would go out whenever the engine was cranked and the old lead line would come in handy at times.I highly recommend this one.
It has all the features:
- Water Temperature
- Bottom type
I've had it for years and never have had to change any batteries.