Actually you have a sub sub lease
. The crown holds the head lease
, the (in our case) Marina company of the yacht club, holds the sub lease and the berth "owner" holds the sub sub lease.
Its not all that uncommon, up until recently the house I owned in Canberra was actually built on land I didnt own, but was on a 99 year government
If the MArina goes belly up you still own the sub sub lease, The head
lease is still owned by the government
so the sub lease can under the crown be revoked by default and reissued to another competent entity. At the end of the day the gummint can save your issue - if they so desire.
Of course we are talking about MSQ here so any preconceptions that sane and decent management will prevail are probably misplaced.