Hi Andy

    We have a 38 Ocean (Year 2000) with the factory fitted holding tank. I had some correspondance a couple of years ago with an owner in Scotland about fitting a tank so I took some pictures of my installation. If you send me your email address (use the Private Message facility) I can send copies of what I have and we can take it from there.

    We can also compare notes on the rest of the boat!

    Where are you based?