Possible Clues:

• One indulging to excess
• Exploitative sort
• One would swear by the employer of the seaman
• Person who over-indulges in, say, drugs or drink
• A British employer, one who uses bad language
• Sadist, e.g.
• Bully, e.g.
• One who reviles or a misuser of drugs
• The employer of the seaman is the one that exploits him
• One could swear that there's transport with 'er