Back to the topic: with uninstalling H3HD and re-installing it to another directory the boat crush disappeared, but I get crushes on ambush events / some guardian mobs while playing original campaigns instead.
Tried to cope with it by avoiding mobs / places which caused these crushes until in 1st map of Long Life the King campaign the group of Zealots guarding quest artifact became game-crushing as well. I tried attacking them with another hero, tried to copy the save into H3Complete and load it there (sadly, HD saves aren't compatible with non-HD older game versions), etc... nothing helped. I can't continue the campaign since w/o that artifact the scenario simply can't be completed.
Here I gave up. I guess I will wait for universal crush fixes after all.
P.S. Horn of the Abyss, having like x5 more buildings, a whole new town, around 20 new heroes, tons of additions to even that of Heroes 3 Complete database, Gigantic maps 256*256 and so much more... won't crush even once. I completed a campaign in HotA and several random maps, including 2 G ones, and including on-line multiplayer game via Hamachi... all without a single crush to Windows. Says much about the "H3HD" quality.