When you are using the word 'tar' to signify a sailor you are exactly not using a word on its own but only a short form of the word tarpaulin and the meaning of this word can unveil the reason behind the use of the word 'tar' being used for a sailor.
Tarpaulin signifies a large sheet that is made with a quite heavy water resistance material and the use of this material is that of to keep the rain off; usually the material does its job by covering things with itself. To some extent a sailor does the same; he keeps the water off and saves all the things that are under his charge. It is for this reason that the word is being used to signify a sailor also.
Tarpaulin signifies a large sheet that is made with a quite heavy water resistance material and the use of this material is that of to keep the rain off; usually the material does its job by covering things with itself. To some extent a sailor does the same; he keeps the water off and saves all the things that are under his charge. It is for this reason that the word is being used to signify a sailor also.