This past weekend I checked the bottom of my Pearson 323. The bottom was pretty clean but the prop and shaft had barnacles. After clening the prop I noticed that the zinc was gone from the prop shaft. I could see where it had been. I couldn't replace the zincs as it was late sunday afternoon. Is this an emergency?? Can it safely wait a couple of weeks or should I make a special trip to replace it this weekend. It's about a 300 mile trip (600 total). By the way cleaning the prop added almost a knot at 1500 rpm!!! 4.5 to 5.5.thanksTom