Azure, between flanches or, a hezant charged with a Bluethroated bird volant proper, and issuing sallirewise from the bezant four frident heads argent.
(Glossary of Heraldic Terms)
The gold discs are intended to represent mines, or segments of them, as they might be observed at very close range from beneath the surface, in reference to the function of the ship as a minelayer. The flying bird represents the name of the ship, while the four tridents indicate protection from approaching dangers.
Bluethroat was originally commissioned as a mine and loop layer in 1955. By 1964 however, she had been redesignated as a research vessel.
Gold and blue.
Badges Of The Canadian Navy by Arbuckle, J. Graeme. Halifax: Nimbus Publishing, 1987.