Hmm, I'd always thought Strv103 needed about 20 minutes prep before swimming. Not so useful in battle.

Are you sure you aren't talking about the Ikv91?

You are probably right on the swimming ability of Strv103 and Ikv91.
It been a while I was listening on the officer that informed us airforce guys what the other branches had to toy with =)

/Antenna

I vaguely recall a screen needs to be erected before it enters the water...

Well if there's going to be an erection involved it had better be warm water...

Wouldn't it need to be warm water in a tunnel?;)

This film from 1971 displays a selection of live fire trials conducted against the S-tank (stridsvagn 103) when it was introduced in the Swedish army in the late 60's. It was shown to the conscripted tank crews as a part of their basic training.

https://www.youtube.com/watch?v=MiWCpIJ5dBw