RSA 450-A:2: Labor.

Any person who shall by himself or others perform labor, furnish materials and expend money in repairing, refitting, equipping or otherwise performing labor or expending money or materials on any vessel, boat, or boat or vessel motor under a contract, expressed or implied, with the legal or equitable owner shall have a lien upon such vessel, boat, or vessel or boat motor so long as the same shall remain in his possession, until the charges for such repair, materials or accessories, money or the like so used or expended have been paid.