There are often disputes about what BBB stands for and I'd like to provide some evidence for its correct interpretation.
From Bridlington Quay and Neighbourhood by Thomas Cape; printed and published at Furby's 'Observer' Offices, King Street. 1877.
"The arms of the town, in heraldic language, are party per pale, sable and argent, three bible B's, two and one, counter-changed. The bearings in the arms of private individuals as well as in those of communities often appear in threes. They frequently had their origin in religious institutions, and may be considered as symbolic of the Holy Trinity: thus Kirkstall had three swords, Selby three swans, and Whitby three ammonites. In this case the division of the Shield, and also, its tincturings and device denote a high antiquity. The letter B was probably adopted from the circumstances of its being the initial letter of the word Bridlington. These arms are figured in Edmondson's Complete Body of Heraldry."
In Historical Sketches of Bridlington [1821, republished 2007], there is this short paragraph: "The arms of the town, anciently one of the priory seals, are party per pale, sable and argent, three Roman B's counter-changed." I think 'Roman' here refers to the typeface and indicates the letters are not in italic.
In The History of the Priory Church, [1836, republished 2008], the following appears: "The arms of the priory have been assumed as the arms of the town. They are given in Bishop Tanner's laborious and useful compilation, the Notitia Monastica, and are per pale, sable, and argent, three Roman B's counterchanged, two and one. The simplicity of the colours and device marks a very high antiquity. The letter B perhaps has reference to the name of the town, and to its being originally a Roman station, and the number, three, was frequently chosen in similar instances to denote, it is said, the Trinity. Thus the arms of the Abbey of Fountains are charged with three horse-shoes, those of St. Mary at York with three swans, and those of Whitby Abbey with three coiled snakes, the snake-stones, or ammonites, with which part of the coast abounds, being traditionally reported to have been originally snakes turned into stones by St. Hilda."
In Folk Lore of East Yorkshire by John Nicholson (published by EP Publishing Limited in 1973, but first published in 1890), a paragraph reads: "The three letters, B.B.B., forming the Bridlington coat of arms, are read as forming the initials of the phrase 'Bad, Beggarly Bolliton'."
It is certain that BBB never stood for that, nor Bright Breezy Bridlington, nor Brave Bridlington Boatmen [used in Come Hell or High Water, the town play of 1995], or even for Benedictine Brotherhood of Bridlington, as stated in an article in Yorkshire Ridings magazine during 2009. That definition is pure invention as the monks in old Bridlington were Augustinians, if that was the intended reference.
As this device can be seen on the side of the Bayle, which has been around since 1388, it is highly unlikely that it refers to any attributes of a town by the seaside, as in Bright Breezy Bridlington. By all means let's use that slogan, but at the same time let's not attribute it to the symbol of the three B's.
Note: Pale: A band placed vertically in the middle of a shield; sable: black; argent: silver [shown white in heraldic illustration]; counter-changed: used of a field divided by a band or other ordinary in which the charges [letter or symbol] in each section are of the colour or metal of the field [background] of the other section.