Steel Adapter, 7/16-20 Male JIC 37 deg Flare To 7/16-20 Male JIC 37 deg Flare, 90 deg Elbow Bulkhead

Marine applications are actually one of the listed use cases for this fitting, so saltwater and offshore environments are right in its wheelhouse. It's a steel 7/16-20 male JIC 37 degree flare on both ends, configured as a 90 degree elbow with bulkhead mounting. The Eaton Aeroquip 2043 series is what you're looking at, catalog number C1AY54, and it carries dimension specs of 1.59 on the A measurement and 0.92 on the B measurement if you're checking clearances before you commit.

Built as a 90 degree bulkhead elbow, it’s meant for situations where you need the connection to pass through a bulkhead and then turn the line. Both ends are 7/16-20 male JIC 37 degree flare, so it’s a straight JIC flare to JIC flare connection with that 90 degree bend.

This Eaton Aeroquip adapter is suitable for marine applications, so it should work well for you. It's also used in chemical processing and offshore drilling, where corrosion resistance is important.