Well the motto 'Vigilanter' means 'Watchfully' or 'Watchful'.
Wiki says it is on these crests
https://www.heraldry-wiki.com/heraldrywiki/index.php?title=VigilanterI think the black coloured birds on the top are crows or ravens and usually signify prophecy, insight, transformation, and intelligence. or, further back, wise messengers or knowledgeable.
Red or “Gules” is the symbol of the warrior, representing might and military strength. It is also associated with being a martyr and represents sacrifice.
COCK: The rooster is the emblem of vigilance, virility, and bravery.
https://en.wikipedia.org/wiki/Symbolic_chickensThere are two half moons wrapped around some hing that looks a bit like the staff from a medical crest
Moon, (fr. lune, lat. luna): the moon is a common device. It is occasionally borne full, when it is termed in fer complement, and it is then figured with a human face. It may also be illuminated, that is, surrounded with very short rays. It proper tincture is argent. When sable it is supposed to be eclipsed.
When a half moon is represented with the horns towards the dexter side of the shield it is supposed to be increscent, and is described as in her increment; when the horns are turned to the sinister side it is supposed to be decrescent, and is described as in her decrement(or, as some blunderingly write it, in her detriment). But these terms are chiefly found in theoretical works, and not often in practical blazon. When the horns are represented uppermost the charge is simply a Crescent, and this from the earliest times was the special ensign of the Turks.
(Decrescent.) DELALUNE.
(Decrescent.) DELALUNE.
(Increscent.) BALSWILL.
(Increscent.) BALSWILL.
Azure, the sun, moon, and seven stars or, the two first in chief, the last in base; [otherwise Azure, seven estoiles in orbicular form, in chief the sun and full moon or]--John de FONTIBUS, Bishop of Ely, 1220-25.
Gules, two flaunches ermine on a chief azure a sun between two moons or--DAY, co. Derby.
Azure, a cross calvary on a griece of three steps argent between a sun in splendour and a moon in her detriment proper--MARTIN, Ireland.
Azure, a moon descrescent or--DELALUNE[or DELALYNE].
Azure, an increscent[i.e. a moon increscent] or--BALSWILL.
Gules, a moon increscent or--DASTURES[or DESTURES].
Azure, three increscents or, each enclosing a mullet--GREGORIE, co. Devon.
Ermine, three increscents gules--SYMMES, co. Northampton.
Increscents are also borne by the families of BUNNELL; BAIRD, co. Haddington; FALLON, &c.
Medical staff of Cadeuceus
https://en.wikipedia.org/wiki/CaduceusWhat was a castle a symbol of?
The castle is a symbol of enclosure, of the walled and defended city;
So around we go...my thoughts are it is either a ship or the crest for a town/village that has meaning for Australian forces.....I am thinking WW1 and in Europe?