Since returning to the game (1.8), it seems a change has been made to disallow the placement/spawning of a boat that would intersect with something (at the same height). This makes the construction of a (vertical) teleboater more difficult, needing to clear out blocks around the block upon which one desires to place a boat. Is there a way to spawn a boat in tight quarters like before, or is it now impossible to do so?
Update: Sand can intersect with a boat by block falling to there, but it seems only at the edge of the boat. Otherwise, the sand block will break upon contact (converting the sand into item drop form).