OK, all my life, I 'knew' the international distress signal as six blasts in a minute. Three blasts is the response. Doing a quick online check, everything I can see seems to agree with this.
I also 'knew' that in the US and aviation, three was the distress signal (be it three fires, three flashes, three whistle blasts).
Recently, I was told by an MRT member that the correct distress signal for use in the UK was three blasts on the whistle and that no-one should blow a response. Now, I understand several reasons why a response would not be a good idea (confusing rescue teams, casualty stopping blowing when they hear it and thus not being located, etc.), but the claim of a change to the distress signal was a surprise.
I can see that aligning with other places would be favourable, but if it has changed, surely this should have spread amongst the community by now?