Aspects of the disclosure relate to systems and fittings for a rain catcher for a marine vessel. A fitting can include a connector body having a first connector end and a second connector end, where the first connector end is configured to connect to a rain catcher of the gravity-fed fluid and the second connector end is configured to connect to a fluid storage tank so that the first connector end is above the second connector end. The connector body defines an interior and an exterior, where the interior is in fluid communication between the first connector end and the second connector end. The fitting can also include one or more ports (e.g., nozzles) laterally defined through the exterior of the connector body and disposed vertically between the first connector end and the second connector end, where the ports are in fluid communication with the interior of the connector body.