If they went there, then you get into sim training for a ditching far out in the ocean or over the polar routes.
Funny you should say that. The ditching sequence in the 737 simulator is very rarely in any syllabus. Where it is trained however, from experience it is rarely performed correctly with the result that the aircraft "torpedoes" into the water due incorrect nose attitude.
Maintaining VREF 40 at 200-300 fpm rate of descent until start of the flare then rotating smoothly to a touchdown attitude of 10-12 degrees while maintaining airspeed and rate of descent with thrust,seems to be beyond the capability of most pilots instrument flying skills. Skill at raw data instrument flying is essential which few possess nowadays it seems.