Main deck and Promenade deck

Main deck noun - The uppermost sheltered deck that runs the entire length of a large vessel.

Promenade deck and main deck are semantically related. In some cases you can use "Promenade deck" instead a noun phrase "Main deck".

Promenade deck noun - A deck at the top of a passenger ship.

Main deck and promenade deck are semantically related. You can use "Main deck" instead a noun phrase "Promenade deck".