To determine which port you have, measure the overall dimension of the frame on the outside of the boat. This is always the most consistent and reliable dimension to use as the defining characteristic of the port.

Known Usage:
• (4 ea) Catalina 315 and Catalina 355
• (4 ea) Catalina 387 (forward, 2 port and 2 starboard)
• (6 ea) Catalina 350, Catalina 400 and Catalina 42
• (8 ea) Catalina 375, and Catalina 385
• (8 ea) Catalina 445
• (9 ea) Catalina 440
• (10 ea) Catalina 470

There may be other uses we are not aware of. They may also not have been used every year the boat was produced.

• Outside of mounting flange (measured on the outside of the boat): 425mm x 191mm (about 16-3/4" x 7-1/2")
• Cut out size: 405mm x 171mm (about 15-15/16" x 6-3/4")

Please note that these ports are built in England and made to metric system standard dimensions. All Imperial equivalents are approximate.

1) With new economic realities restricting the inventory levels of even major manufacturers like Lewmar, if we don't happen to have one on the shelf, we may have to wait for one to be made in the UK. In that case, delivery may take in the neighborhood of 5 to 6 weeks. Lewmar Stainless Steel Size 7RE, C-315, C-355, C-375, C-385, C-425, C-445