Rawtenstall’s Hamer, clocked a time of one minute 56.58 seconds, just 0.26 seconds behind China’s Wai Lok Tang who took gold. Australia’s Daniel Fox won the bronze medal in a time of one minute 56.69 seconds.
Hamer lay in second place at the turn, powering back in the final 25 metres to draw level with Tang, but the Chinese swimmer touched first in what was an almost blanket-finish.
The 18-year-old made his international para-swimming debut at the 2014 Commonwealth Games in Glasgow, before going on to win bronze medals at both the World and European Championships a year later.
The former Alder Grange pupil who trains at the Manchester National Performance Centre, has set British records in the 50m, 200m and 400m freestyle S14. He still has the 200m individual medley SM14 event remaining at these Games.
Great Britain is in second place on the medals table at the end of day four with a total of 55 medals, of which 22 are gold.