Thanks for your reply, I've seen your many many helpful replies to other recipients while browsing the forum I'll have to look at the RONDO cover and sportband when I get back into the swing of things.
For you and anyone who is interested, I messaged MEDEL directly as well earlier on as well in case they had some rough figures- they've given a surprisingly prompt reply. The long and short of it is
1. The bonebridge has been pressure tested up to 6 BAR (equivalent to a diving depth of 50m) without any damage being caused to the implant. The Floating Mass Transducer (FMT) does not sit tightly in the well that is drilled into the mastoid bone, so there is air around it, however the elasticity of the skin flap overlying the implant allows for some expansion of air within that space (relevant to pressure changes when diving).
2. As expected, BB recipients are strongly encouraged to use head protection whenever possible during sports and activities in which head trauma may occur by accident, and are not recommended for sports where blows to the head are common (eg boxing or martial arts that include contact with the head).
What does this mean for me, personally? I think that I won't be engaging in martial arts again anytime soon, likely ever, unfortunately. I'm a little bit more cautiously optimistic about diving, although that will be a fair while away at any stage and well, well within the depth distance tested. This is my own personal opinion though.
I stress that each operation would be operator and patient dependent (including complexity and location of surgery) and the advice of the individual surgeon should be sought in regards to any decisions made regarding the above, and again that no real recommendation or advice was provided by the representative who responded re diving, simply the facts. I am actually very impressed at the prompt and detailed nature of the reply.
Again, thank you Ivana and best wishes to the rest of the team,