Just picked up an early model Seafari 20

[Bikecop1]

I looked it up. No dice.
The Discharge Of Waste
All boats, including houseboats and floating cabins, equipped with a marine toilet must have a waste-water holding system to prevent the discharge of waste products into surrounding waters.

A marine toilet is considered to be any equipment for installation onboard a boat which is designed to receive, retain, treat or discharge sewage and any process to treat such sewage. A "porta-pottie" is not considered to be a marine toilet. This figure shows a typical marine sanitation device:

Image of a typical marine sanitation device

It is illegal for a boat to pump out sewage from a waste-water holding system or from a portable toilet or marine sanitation device into surrounding waters, except into an approved pump-out facility or into a sewer system located on dry land.

All boats equipped with a marine toilet must be registered with the Georgia Department of Natural Resources. You will be issued a Marine Toilet Certificate decal which must be affixed to the hull adjacent to the boats registration number. The one-time certification fee is $5.00. No renewal of the certificate is required and it is transferable to any subsequent owner of the boat.