shelter deck vs weather deck

shelter deck and weather deck both are nouns.

Word	Noun	Adjective	Verb	Adverb
shelter deck	Yes	No	No	No
weather deck	Yes	No	No	No

As nouns, shelter deck and weather deck are synonyms defined as:

shelter deck and weather deck: upper deck having no overhead protection from the weather, but sheltering the deck below

shelter deck (noun)	weather deck (noun)
upper deck having no overhead protection from the weather, but sheltering the deck below	upper deck having no overhead protection from the weather, but sheltering the deck below