seized seacock

[shindig]

Hi all....as is good practise i tried to operate the seacocks on the Simson-Lawrence sl-400 toilet on my Atlanta 25....the outlet one was, as it should be at dock, inthe closed position but opened fairly easily...the inlet one would not budge....I hope its is in the closed position!....they appear to be gate-valve types, with normal "tap" handle fitting onto a square end.......ther is only one handle which swaps from one seacock to the other....any advuice on freeing this up....with the boat in the water?

haven't checked the others yet....

[shindig]

hi all...tried again and managed to unscrew by extending the lever, though it is still very stiff compared to the outlet seacock......any tips on any further maintenance i should be doing these....i shall continue with unscrewing/screwing on a regular basis