What is a "Real Sailor"?

my dad and I went to Annapolis today to see a couple friends of my Dads. I asked my dad what they did (they are all in the Navy) and he said, verbatum "these mother ******* are the real ******* deal, they are real sailors, they are the saltiest Motherfuckers ive ever been around". Im wondering, what is my dad meaning by a real sailor?