James Robertson - Ships Carpenter - Peterhead area

[celticmutt]

I'm seeking information concerning the above-named individual - my 4th great-grandfather.  He was probably born in the late 1700's because he was already a ship's carpenter when he married Margaret Skinner in Peterhead in 1816.  They had a son (also James) born in 1818.  The elder James was probably lost at sea (I can't find death or burial records) and Margaret was re-married to a John Lucas in 1826.  Due to the commonality of the name and the fact that there aren't any death records, I'm having a difficult time nailing down the elder James.  Margaret was born in Glass in 1798.
Any input would be greatly appreciated.
Bill Robertson