Greenland 34: Head Effluent Discharge Thru Hull

[Marcsailcat]

We have a 34 Greenland FP power cat. The forward head discharge thru hull is located about 3 inches above the water line. I noticed that the thru hull is located in the same place on the Highland FP model.

FP has plumbed the boat so that the head pumps to the holding tank. The holding tank can be pumped out from the deck fitting or drained by gravity via the thru hull.

This arrangement is fine if you are 3 miles or more offshore to discharge. However not fine in a marina! So I am re-plumbing my boat with an onboard treatment system (Purasan) and larger holding tank (going from a 14 gal to a 25 gal). I plan to use the holding tank in no discharge zones and use the Purasan everywhere else.

My question is- should I relocate the thru hull fitting to below the water line for the Purasan discharge?