U S Navy Flag (horse)

U S Navy Flag began his racing career in a maiden race over five furlongs at Naas Racecourse on 1 May in which he started at odds of 11/2 and finished fourth of the six runners. He ran third in a minor race at the Curragh twelve days later and was then stepped up in class for the Listed Marble Hill Stakes at the same track in which he finished third to Brother Bear. In June the colt was sent to England to contest the Group 2 Coventry Stakes at Royal Ascot but made little impact as he came home fourteenth of the eighteen runners behind Rajasinghe. The colt was then dropped back in class for a maiden at the Curragh of 1 July and was equipped with blinkers for the first time. Ridden as on his four previous starts by Seamie Heffernan he took the lead from the start and won "comfortably" by three and a half lengths.[4]

Twelve days after recording his first success U S Navy Flag was sent to England for the second time for the July Stakes at Newmarket Racecourse in which he was partnered by Ryan Moore. Starting at odds of 10/1 he led for most of the way but was overtaken in the closing stages and beaten by the Mark Johnston-trained Cardsharp, with Rajasinghe in third. At the Curragh on 13 August the colt was partnered by his trainer's son Donnacha O'Brien when he was stepped up to Group 1 class to contest the Phoenix Stakes. He attempted to make all the running as usual but was outpaced in the final furlong and finished fourth behind his stablemate Sioux Nation, beaten two and a half lengths by the winner. Two weeks later the colt started 5/4 favourite for the Group 3 Round Tower Stakes over the same course and distance. With Moore again in the saddle he produced his customary front-running display before drawing away from his opponents in the final furlong and winning by six lengths from Landshark.[5]

On 30 September at Newmarket, U S Navy Flag, ridden by Heffernan, was one of twelve colts to contest the Group 1 Middle Park Stakes over six furlongs and started at odds of 10/1. The Railway Stakes winner Beckford started favourite, whilst the other runners included Sioux Nation, Cardsharp, Rajasinghe, Unfortunately (Prix Morny) and Sands of Mali (Gimcrack Stakes). U S Navy Flag tracked the leader Hey Jonesy before taking the lead approaching the final furlong. He held off the sustained challenge of his unfancied stablemate Fleet Review to win by half a length, with a gap of two and a quarter lengths back to Cardsharp in third.[6] After the race O'Brien said "He takes his racing well and is progressing with every run. He is long and he is powerful. I think he will go down the sprinting route, but there is nothing to say he won't get seven. He is a hardy horse that is progressing and when horses are like that, you can keep going with them". Heffernan added "He's a horse that's a bit gawky and looks around, so the blinkers help him focus and make the jockey's job easier".[7]

At Newmarket on 14 October U S Navy Flag attempted to become the first horse since Diesis in 1983 to follow up a win in the Middle Park Stakes with a victory in the Dewhurst Stakes. Racing over seven furlongs for the first time he was ridden by Moore and went off the 5/1 second choice in the betting behind Expert Eye, a colt from the Michael Stoute stable who was unbeaten in two races including the Vintage Stakes. The other seven contenders included Cardsharp, Emaraaty and three other Aidan O'Brien-trained runners, namely Seahenge (Champagne Stakes), Threeandfourpence and Mendelssohn. After breaking quickly Moore brought the colt over to the rails on the stands side (the left hand side from the jockey's viewpoint) and set the pace from the start. U S Navy Flag opened up a clear advantage approaching the final furlong and kept on "strongly" to win by two and a half lengths from Mendelssohn. Seahenge and Threeandfourpence came next to complete a 1-2-3-4 for the Ballydoyle stable.[8] O'Brien commented "I think he was overlooked a bit, wasn’t he? He's a tough, hardy horse. A very exciting horse really."[9]

On his final appearance of the season U S Navy Flag was sent to California to contest the Breeders' Cup Juvenile at Del Mar Racetrack on 4 November. Racing on dirt for the first time he led for most of the way before dropping back in the last quarter mile and finishing tenth of the twelve runners behind Good Magic.

U S Navy Flag made his seasonal debut in the 7 furlong Leopardstown 2,000 Guineas Trial Stakes on 14 April. He was sent off at odds of 6/1 in a field of four runners which included two stablemates in Gustav Klimt and Kenya. Ridden by Seamie Heffernan, U S Navy Flag raced in second place early in the race but dropped away to finish last of the four runners.[10] The race was run on heavy going and O'Brien stated "We knew US Navy Flag would hate the ground, but we needed to get him out [he] might go to the English or French Guineas and he'll grow another leg between now and then."[11] In the Poule d'Essai des Poulains over 1600 metres on 13 May he led for most of the way but after stumbling badly he was overtaken and faded to finish fifth behind Olmedo. Thirteen days the later the colt started second favourite for the Irish 2000 Guineas at the Curragh. He took the lead from the start and maintained his advantage until the last 100 metres when he was passed by the 25/1 outsider Romanised and beaten two and a quarter lengths into second place.[12] In the St James's Palace Stakes at Royal Ascot the colt set the pace as usual but after being headed in the straight he dropped back quickly and came home ninth of the ten runners behind Without Parole.

On 14 July U S Navy Flag was dropped back to sprint distances to contest the July Cup over six furlongs at Newmarket and started at odds of 8/1 in a thirteen-runner field. Blue Point started favourite while the other contenders included Eqtidaar, Limato, Sands of Mali, Sioux Nation, Redkirk Warrior (Newmarket Handicap) and Brando (Prix Maurice de Gheest). Ridden by Moore, U S Navy Flag raced up the centre of the course and led the way throughout, keeping on well in the closing stages to win by one and three quarter lengths from Brando, with third place going to the 50/1 outsider Fleet Review.[13] After the race Moore said "He loves Newmarket and ran a mighty race in the Irish Guineas. He's just a very fast horse and loves a fight – he found plenty when the second came to him. I was never worried about the trip, he just needs to have fast ground" while O'Brien commented "He had tough races in the Classics and had a very tough race in the Curragh. We thought it might leave his mark. He went to Ascot and Ryan said to come back in distance with him. We've seen what's happened. He's a very good horse, to be able to do it that as a three-year-old. In all fairness to the horse, he deserves a break. He's had a tough time".[14]

In the autumn of 2018 U S Navy Flag was sent to race in Australia but had no success as finished unplaced in The Everest, the Manikato Stakes and the VRC Sprint Classic.