Well, I went for years without one. I bought one from Cabelas which only works 10% of the time...I do like them alot..
Questions before I buy my next one..

1. What brand do you have?

2. Cost?

3. Can I clamp it to the bottom of my trolling motort? I won't drill any holes in my boat.

4. How long have you had yours?

Thanks,
Chuck7