Second to arrive is Joshua Slocum. A fairly obvious choice, but fuggit, it's my dinner and I can invite who I want. I'd love to hear about Capt Slocum's final sail, and hear the sea stories that didn't make it into the book. When he arrives at the Spouter-Inn he thanks Shackleton for the Guinness and sits at a table by himself, though he does chat amiably with all who muster the courage to approach.
Next is another hero: Joseph Conrad. Sailor and Author. I'm pretty sure English was his third language (behind Polish and French). Heart of Darkness. Fulk. Secret Sharer. Victory. Typhoon. His third novel. And Lord Jim, the one I can never get through. I'm sure he'd tell some interesting sea stories.
Next is Cayard; then Vito Dumas because I think he's hilarious; Valerian Albanov, also not from Wussbagia; and good, old Herman Melville: you gotta have the author of Moby Dick over for dinner when you can!
Eat, drink, and be merry!