Lodges of Royal Ark Mariners assume the number of the Mark Master Masons Lodge to which they are attached. The Degree does not have a Provincial or District structure, it is governed by the administration for Mark Master Masons in each Province.
Qualification for membership is that of Mark Master Mason. A candidate for the Chair of Worshipful Commander must have been Worshipful Master of a lodge of Mark Master Masons, but a dispensation can be applied for where this is not the case.
There are 20 Lodges of Royal Ark Mariners meeting in Warwickshire.