It seems to me that light aircraft who operate around water might, if it didn’t weigh too much, have the equivalent of emergency water landing gear that would activate automatically if they had to crash in water.
This would not be what you might typically think. For instance, a common problem is that the plane hits nose first and flips on its back. A system so that it belly lands would be a huge help.
Other things along those lines could save a lot of lives, and if intelligently designed, not at the expense of too much weight or cost.
The best option for ditching in water, next to having a seaplane or float plane, is to have a plane equipped with retractable landing gear which you would leave up. The gear hanging down is what usually causes rapid deceleration and resulting flip.
It's a major reason fish spotters who spend enormous amounts of time over water in single engine aircraft use those with a long loiter time and retractable landing gear. A favorite is the Cessna 172RG and a company here in S. Louisiana has about 20 of them.
If you have to ditch in water, your options are doing so during daylight hours, how close you can get to land or a boat, and wind and wave direction.
I believe the aircraft pictured below is the particular aircraft used. If was the Cessna 208, it doesn't have retractable landing gear.
