"I live on an island in NW Washington, as a result I obviously do a lot of flying over water. I have a Socata/Tobago TB 10 with fixed gear and gull wing doors. The question is - given a choice with an engine failure, would you recommend an emergency landing in shallow water near the shoreline or go for a tall stand of pine trees? There is no guidance in the POH." - Anonymous
“Of course our first answer to this question is neither one. I would work hard to keep myself from having to make this choice.
As a glider pilot, we have a rule that we do not fly over unlandable terrain unless we are high enough to glide to landable areas. I try to follow that same rule as much as possible when flying a power plane. But, that does not answer this question.
The first place to always go for questions like this is the pilots operating handbook, since you say there is no guidance there, I suggest you write the manufacturer to see if they have published any data on the subject. I did a quick review of the NTSB and AOPA accident data bases and found nothing related to Socata TB10 ditching.
History shows that landing a fixed gear aircraft on the water usually results in the airplane flipping over with some serious G forces in the stop. Now you are upside down, disorientated, perhaps injured and face a possible drowning. Not a pretty picture. I recently read of a Piper Warrior landing in a river and it turned over on the landing and two of the passengers drowned.
In my opinion, a tree landing is a better choice. While there are of course many hazards about a tree landing, pine trees are a soft wood that give way as they dissipate the energy which help in reducing the deceleration forces. Further if you or any of your passengers are injured, they can stay in the plane until rescued without fear of drowning.
I sincerely hope neither you or I have to make this choice in our flying career.”