Lets carry a minisub held on only at the docking collar of a nuclear submarine at full speed with no external shelter. We'll make it dry so it can't be flooded to equalise pressure with the outside as well.

Water pressure increases 1 atmosphere for every 10m of depth. I'm guessing that one of these nuclear powered mother subs can go a *lot* faster than and dive a *lot* deeper than than their planned ASDV. The forces on any mechanical linkage (like the hydroplanes on the ADSV or between the sub and its docking collar) are likely to be *large*.

So handicap the mother ship performance all the time or have it compensate for the nose weight of shelter + vehicle.

A hugely ambitious upgrade program which is killed after swallowing vast expense and leads to reversion to much less ambitious version instead.

Have the septics had someone on secondment from the MoD perchance?

Mine will be the one with "Project Management for Dummies" in the pocket.

IIRC standard (and they have been since the time of Whitehead) Western torpedo tubes are 21" in diameter, that's a 65" waist. More than enough even for my less than sylph like figure. But what about the back pack? Is there a discrete "cough" of compressed air option on these things. I got the impression torpedo ejection is fairly violent.