Sea Of Class was a light-coloured chestnut filly with no white markings bred in Ireland by the Italian-based breeding company Razza del Velino SRL.

After being restrained by Doyle in the early stages she went to the front approaching the final furlong and won "comfortably" by two lengths from Mrs Sippy.

[7] On 21 July Sea Of Class was the only British-trained filly to be sent to Ireland to contest the 2018 running of the Irish Oaks over one and half miles at Curragh and was made the 11/4 second choice in the betting.

She moved into second place behind Forever Together entering the final furlong and caught the Epsom Oaks winner in the last strides to win by a neck under a "hands and heels" ride.

[13] Four days later the filly started the 5.4/1 joint second choice in the betting for the race over 2400 metres at Longchamp Racecourse despite being drawn on the wide outside.

When asked for advice on how to deal with the unfavourable draw the trainer's father-in-law Lester Piggott said "Don't change the tactics, drop her out the back and pray".

[16] On her four-year-old debut, Sea Of Class started the 5/1 fourth choice in the betting for the Prince of Wales's Stakes over ten furlongs at Royal Ascot on 19 June.

The race was run in very difficult conditions, with the course being swept by heavy rain and the filly never looked likely to win, coming home fifth of the eight runners behind Crystal Ocean.

On 3 July 2019, Sea Of Class underwent colic surgery to remove a mass, which turned out to be a malignant lymphoma, and part of her gut.