Something else...
Something I thought about in regards to the PF. If you are to ditch, what will you aim for? You are looking to minimize the break up of the airframe's structure in order to increase the chances of survivability. I remember from my PPL days that the CAA produced around 14 documents relating to all levels of airmanship matters (see a copy of UK LASORS, I believe they are all included here). One I believe included 'ditching.' Although relating to GA aircraft types, it did take into consideration the effect of swell and waves and what the dangers were when preparing for a landing on water. I understand the most recent copy of Flight talks about this as well, including the possible outcome to the Hudson A320, had conditions on the day been different and indeed if the crew hadn't done such a spectacular job.