i like west marine although I always shop at Svendsen's chandelry when I can (way better). I like it because it is there as opposed to nothing. Even in the SF bay area, there are not so many other generalized marine store and it is quite useful on a Sunday afternoon.
I found people to be friendly and a few to be quite knowledgeable. You just have get the feeling for who knows what. One guy steered me away from the expensive fiddles and encouraged me to make my own for example, so they are definitely not all vultures as some claimed in other threads
and yes, they were good at replacing my handheld when the GPS died on me