400: galley sink drain through hull

[johnamie]

New Lagoon 40 owner (hull 238) - Does the galley sink drain through hull have a shut off to allow diversion into holding tank or is it always open? I can't seem to find the shut off if there is one. The owners manual shows where the line goes, you can see drainage from the sink coming out above the waterline, but no obvious way to access where the through hull might be. John