Necessaries: maritime supplies creating liens depend on whether they are reasonably fit and proper for the vessel The concept of necessaries in maritime law covers goods and services reasonably fit and proper for a vessel's business and voyage rather than only items indispensable for life; the test asks whether a prudent owner would have authorized the expenditure given the ship's character, voyage, port conditions, and exigencies, and both physical necessity and commercial operation are relevant factors in creating an admiralty lien.