The USN and USCG banned beards in the mid-1980s except for those with exemptions for skin conditions who can grow a maximum of 1/4". Recently it allowed beards for retired personnel while wearing uniform. It also recently lost a court case which means beards can be warn for religious reasons.
Adm. James Watkins, the chief of naval operations at the time, explained his decision requiring sailors to shave by saying he had determined that few service members had beards, making those who do appear “extremely un-uniform,” according to an Associated Press report published shortly after the prohibition took effect.
Watkins added that beards could pose a safety hazard in such contingencies as oxygen mask wear. Mustaches were not covered by the ban, the AP noted. The service does regulate their size and length, though.
This reg amused me - I am sure we all agree on the FOD point
2201. PERSONAL APPEARANCE
(...)
3. HAIRPIECES. Wigs or hairpieces shall be of good quality and fit, present a natural appearance and conform to the grooming standards set forth in these regulations. They shall not interfere with the proper performance of duty nor present a safety or FOD (Foreign Object Damage) hazard.
In the UK, the senior service's regulations remain more conservative than those of the junior service.
BRd 3(1) Chapter 38
3818 Male Personnel
a.
Hair. Hair shall be neatly groomed; taper trimmed at the back, sides and above the ears to blend with the hairstyle. On the top of the head it shall be no more than 15 cm in length and sufficiently short at the front and sides that when the hair is groomed, and headdress removed, no hair shall touch the ears or fall below the top of the eyebrows. It shall be kept above the shirt collar. Cultural and religious exceptions are described at Para 3827(
Sikhs) and Para 3828 (
Rastafarians).
b. Hair shall be no greater than 4 cm in bulk at the top of the head, with the bulk decreasing gradually from the top and blending with the taper-trimmed back and sides. Bulk is defined as the distance that the mass of hair protrudes from the scalp when groomed, as distinct from the length of the hair. Styling shall not present an exaggerated or non-conformist appearance, nor shall it interfere with the proper wearing of headdress. Excessively short hair can detract from a smart and well-groomed appearance, however, it may be permitted at the discretion of the Commanding Officer. Unnatural hair colours (ie. those colours that are not within the colour range of the individual's natural hair colour) are not permitted.
c.
Sideburns. Sideburns shall not extend below the ear lobe, shall be of even width, and shall be taper trimmed and squared off to conform to the overall hair style. Sideburns for RM Personnel shall not extend below halfway down the ear.
d.
Beards and Moustaches. The Commanding Officer may permit all Naval Service (except RM) male personnel to request to wear full set beards. RM male personnel may wear moustaches at their discretion. Beards and moustaches shall be kept neatly trimmed especially, in the case of beards, at the lower neck and cheekbones. It is within the subjective judgement of the Command (and delegated representatives, namely the Executive Dept and all personnel in positions of authority (LH/LCpl and above)) to define an acceptable appearance of a beard, as much depends on the features of the individual. However, as a guide the following characteristics are not acceptable:
(1) 'Designer Stubble'. Designer stubble is assessed as any beard length shorter than Grade 1 (2.5mm).
(2) Beards of Uneven Growth (eg. 'scrappy'). The definition of 'scrappy' remains within the subjective judgement of the Command (and delegated representatives, namely the Executive Dept and all personnel in positions of authority (LH/LCpl and above)).
(3) Extended or 'hipster' Beards or ‘handlebar’ moushaches. Extended or 'hipster' beards or ‘handlebar’/extended moustaches are not appropriate. The maximum acceptable length of a beard is to be Grade 8 (25.5mm).
(4) Beards Taking Excessive Time to Grow. The definition of an 'excessive amount of time to grow' remains within the subjective judgement of the Command (and delegated representatives, namely the Executive Dept and all personnel in positions of authority (LH/LCpl and above)). The advised maximum time for an individual to grow a sufficiently thorough beard is 2 weeks.
(5) Religious or Faith Reasons. Where facial hair is grown as a tenet of a faith by a genuine adherence to that faith, it may be grown in excess of the limit described above at sub para (3). Such facial hair may require to be trimmed, however, or be tied up or removed if it undermines the health and safety of the wearer or others in the unit, or if it undermines the operational effectiveness of the unit. Any faith or practice must be clearly established by an individual and not simply deemed as having been undertaken in order to defy the regulations contained within this BR.
e. When the safety of an individual might be jeopardised by his beard or moustache, such as in the wearing of oxygen or gas masks, it shall be modified in such a fashion as to accommodate the type of equipment to be worn. The Commanding Officer retains the authority to determine the requirement for an individual to shave, based on the Operational requirement at that time. Once ARTS testing has been completed, COs ARE to order the shaving of beards when the CBRN threat level is MEDIUM or higher. Other occasions, such as Operational Sea Training and/or similar exercises, in which the CBRN threat is LOW will not warrant the requirement to shave. If the individual refuses to modify their facial hair (or headdress) to the extent necessary to maintain their own safety and Operational Capability, then they may be disciplined. Should they continue to refuse, commanders should consider not deploying that individual into theatre or removing them from theatre if already deployed. Disciplinary action and non-deployment are in extremis measures that should be adopted incrementally.
f. Beards or moustaches shall be shaved off if the conditions of Para 3818 sub para e cannot be met.
g. In addition to the guidance at Para 3818 sub para e, the Command may order individuals to shave off beards deemed inappropriate for a Service Parade of any nature.
h. Beards should be of a length that does not extend beyond the top part of the collar front of a service shirt. More specifically, if the Naval serviceman was wearing a shirt and tie, the beard would not obscure the knot of the tie. The breadth of the beard should not exceed the maximum width of the line between the Naval serviceman’s ears.