It happens, here is an excerpt from an ATSB report into a Qantas jet that had prepared for a 'ditching' before deciding to carryout an autoland into Perth where no such facility existed:
FFS, the Qantas jet did not prepare for a 'ditching' before deciding to carryout an autoland. They were simply pointing out that since a ditching was the only alternative to an autoland, their decision to autoland below minima was fully justified.
They made two go-arounds, and on the third approach said "we're landing off this one". As you would.