Paul
As I have now taken over Bill Parker's web site we are often in conversation on the phone. I brought your posting to his notice and I know that he rang you to discuss your concerns this past weekend.
I have seen your latest posting but I thought it wise to pen a fuller reply on behalf of Bill (with his permission) for the benefit of other owners and prospective owners.
The conversation went like this....
'The water tanks were moved forward from under the steps to improve the ballast, especially for people who carry heavy engines and plenty of fuel.
To reduce the possibility of water sloshing out of the tank in use, one should ensure the pipe curves as high as possible in the form of a swan neck. He also suggests that if one wishes to sail with tanks that are filled to the top that one drills a hole in the cap, sufficient to take the outlet pipe, so leaving the cap in place.
The sea water ingress was caused by the ball valves being left open. It does state in the manual that these should be closed when sailing (in fact this goes for all boats).'
I would like to add that although the Parker 325/335 have 45 gallon water tanks, we do carry two water containers under the sink for fresh drinking water. You state that when pulling the pipe out of the tank when changing over, that water flows out of it into the compartment. I had the same problem until I realised that before pulling the pipe completely out of the tank, I lift it clear of the remaining water then pump the handpump to clear the pipe. Problem solved.
Best regards
Don
Don Harvey