Why Are Sailing Terms Pronounced Like They Are?

You need to be more specific - terms in any outdoors context are basically pronounced as they are for clarity in extreme conditions.

Many words in sailing are derived from terms used many years ago and evolved into the words used today. For instance the word "starboard" meaning right comes from the term "stearing board". When boats were pointed at each end the rudder or "stearing board" was on the right side of the stern. Over the year "stearing board" meaning the right side became "starboard". "Port" being the opposite side or the left side came from the fact that you would not want your "stearing board" up against the dock or  the port because you cound not stear your boat away from the dock. Consequently the left side or the "port" side was always againest the dock thus giving the term "port" side.   A.R.(Jack) Way