Students who join the URNU are members of Royal Naval Reserve and upon joining hold the rank of Officer Cadet,[1] and can progress to the rank of "Honorary" Midshipman, the position is Honorary due to the Officer Cadet not holding a Commission in the RNR.

[4] Each unit has an affiliated P2000 ship, which is used for training Officer Cadets when not on duty with the Coastal Forces Squadron.

After being male-only units for their first 20 years, the URNUs finally allowed women to join their ranks in 1987, with the Aberdeen URNU being the first to do so.

[15] URNU Officer Cadets have been attending the exercise every year since, with the exception of 2022, due to increased tensions in the region following the re-escalation of the Russo-Ukrainian War.

They fall under the overall jurisdiction of the Commanding Officer of Britannia Royal Naval College, Dartmouth, Captain BRNC.

Each URNU comprises 51 students, who usually join for the duration of their degree, with the option of taking a year out or leaving at any time.

Once a certain number of points has been acquired, students will wear Midshipman rank slides in addition to URNU tabs and are referred to as Acting Midshipmen (A/Mid).

To achieve the substansive rank of Midshipman the URNU OC must pass out of BRNC via the reserve or regular courses.

Training focuses on leadership, navigation and seamanship, and this is put into practice during sea weekends, and longer deployments during the summer and Easter vacations.

There is also a significant and important social element to URNU life from formal mess dinners including the main naval formal event of the year, Trafalgar Night, to informal socialising in the unit's mess which contribute to unit integration and may be coordinated by a dedicated social secretary.