On the deck oversea.
Not sure of his fit but we were small tanks, outboard ECM. I vaguely recall we both slowed to around 300kts then on a head nod (we were quite close) hit the reheat. Both slowed somewhere north of 600kts before we went s/s. This was a GR1 with 103 engines.
Only took a few seconds so couldn't have been more than a few miles.