2018–2019 For the
2018 Pan Pacific Swimming Championships, held in August in
Tokyo,
Japan, Sloman was named to the
Swimming Australia roster. He competed in the
10 kilometre open water swim on 14 August, where he won the bronze medal with a time of 1:59:20.8, which was 30.3 seconds behind gold medalist
Jordan Wilimovsky of the
United States and 24.1 seconds behind silver medalist
Eric Hedlin of
Canada. At the 2019
Surf Life Saving Australia Championships in March in
Burleigh Heads, Sloman won the national title in the 2 kilometre ocean swim along with
Lani Pallister, who won the women's title, marking his third-consecutive title in the event. He followed up with a silver medal in the 10 kilometre open water swim at the leg of the
2019 FINA Marathon Swim World Series held in May in
Seychelles with a time of 1:56:04.10. Two months later, at the
2019 World Aquatics Championships held in July in
Gwangju,
South Korea, he placed twenty-first in the
10 kilometre open water swim on 16 July, finishing in a time of 1:49:22.7. Two days later, he placed fifth in the
5 kilometre (4×1250 metre) open water team relay with a final relay time of 54:36.8.
2022 2022 World Aquatics Championships In March, Sloman was one of six swimmers named to Team Australia in
open water swimming for the
2022 World Aquatics Championships in
Budapest,
Hungary. On 26 June, he helped achieve a sixth-place finish in the mixed gender
4×1500 metre open water relay with a time of 1:05:30.8. In his second event, the
5 kilometre open water swim the next day, he tied Brennan Gravley of the United States for tenth-place with a time of 54:28.4. For his third and final event, the
10 kilometre open water swim held on 29 June, he finished in a time of 1:51:58.1 and placed eighth, which was 1 minute and 1.3 seconds behind gold medalist
Gregorio Paltrinieri of Italy.
2022 Marathon Swim World Series At the second leg of the
2022 FINA Marathon Swim World Series, held in July at
Parc de la Villette in
Paris,
France, Sloman won a silver medal in the 4×1500 metre open water relay in a time of 1:08:03.75. He also finished in a time of 1:51:41.95 in the 10 kilometre swim and won the bronze medal. The following leg, conducted in August at
Lake Mégantic in Canada, he won the silver medal in the 10 kilometre open water swim with a time of 1:50:51.68, sharing the podium with gold medalist
Domenico Acerenza of
Italy and bronze medalist
Dávid Betlehem of Hungary. He won a second silver medal in the 4×1500 metre open water relay at the final leg, with competition held in November in
Eilat,
Israel, helping achieve a final time of 1:06:36.60. For the 10 kilometre swim he placed eleventh with a time of 1:46:56.60. Across all of the legs of the World Circuit for the year, he earned 1600 points, tying for rank of sixth overall with
Dario Verani of Italy amongst all male competitors.
2023 In January 2023, at the year's Australian Open Water Championships, Sloman finished in a time of 55:20.96 in the 5 kilometre open water swim to place second less than one-tenth of a second behind
Kyle Lee. Two months later, he was named to the
2023 World Aquatics Championships roster for Swimming Australia in the 10 kilometre open water swim. In April, at the
2023 Australian Swimming Championships in
Gold Coast, Queensland, he won the bronze medal in the 1500 metre freestyle with a 15:18.20 and placed ninth in the 400 metre freestyle with a 3:55.98. ==International championships==