A traditional maritime lien is a secured right in the "res", i.e., in the property of another (ordinarily the ship), which arises with the claim, without registration or other formalities; it travels with the vessel even if it is sold to third party; which remains with the vessel until it is enforced by an action in rem; and which, when so enforced, gives the owner of the lien the claim priority in ranking over most other claims, notably ship mortgages.

In U.K. and Commonwealth countries, the term "maritime lien" applies only to limited maritime claims, being seamen's wages, master's wages, master's disbursements, salvage, damage (caused by the ship), bottomry and respondentia. These are known as "traditional maritime liens". 

Other maritime claims resulting from services supplied to the ship or damages done by the ship, notably claims for "necessaries" provided to the vessel (e.g. bunkers, supplies, repairs, and towage), as well as claims for cargo damage, for breaches of charter party and for contributions of the ship in general average, do not give rise to "traditional maritime liens" in but only to "statutory rights in rem" subject to fulfillment of certain conditions.