This comes from French. "Mer" is "sea" (hence the word mermaid) and "sur" is a preposition, "on" or "above". "Sur-mer" is seaside.
the sea (it should be - la mer)
"Mer" means "sea."
It means: "from the sea the sea"
from seas
à la mer means in the sea or at the seaside
"La Mer" means "the sea" in French.
"de la mer à la mer" means "from the sea to the sea" (from one ocean to another, as in the Canadian motto, that you can also find in Latin) -
there is the sea!
Sea
Chance à la mer means "Luck at sea". You would probably want to say Bon chance à la mer, or Good luck at sea.
naked as the sea
Mal de mer is an expression literally translating into "sick of sea" or "bad of sea." In English, we know it as "seasick."