I've got the marine fuse block and am wiring a scanner and some fogs up to it. I've read some people using a circuit breaker. Is this really necessary since there are the fuses? Also, if it is necessary to get one, is this going to be the right one?

http://www.bluesea.com/product.asp?Product_Id=26525&d_Id=7407&l1=7407&l2=

thanks