I had a service
when the boat was in the water in Marina Del Rey...my problem with them is that they'd leave a tag telling me they had been there (thanks!), and then giving me their evaluation of the through-hulls, zincs, prop, rudder
, etc. One month they'd be in just fair condition, the next they'd be in excellent condition, etc.....
Once the tag had a hand-written warning about the prop zinc being missing. Well, MDR is a very hot marina. So, instead of going sailing I got the wetsuit, zinc and tools out and went diving
The zinc was there, and looked like it was 85-90% intact.
As far as goosenecks go, they will attach to a moving boat. But, they require flowing water and will die and drop off after you're in a harbor for a few days.