"Sea lawyer" is also US Naval slang for a sailor who has an intimate knowledge of the rules and regulations (or thinks he does). The sea lawyer makes an unholy pain in the ass of himself by forever quoting rules that "excuse" his laziness and bad behavior -- especially his unwillingness to do what's required of him. The sea lawyer never just shuts up and does his damn job.
My understanding is that it's not a complimentary term. "Malignant parasite" might be a close synonym, perhaps?
We get a local equivalent of these on E2 sometimes. Other services have their own terms for the same deal: Barracks lawyer, etc.