I have been having this same exact issue, apart from the boat part, I never really go on boats in Minecraft.
Basically, for me, whenever I play the game, it launches and plays smoothly without many issues, apart from small lag here and there, then after about 20-30 minutes later, the game suddenly freezes on me, unfreezing for a brief second, before freezing again and crashing completely. This has never happened before until 1.6.0.8 released.
Steve Whiller
I have been having this same exact issue, apart from the boat part, I never really go on boats in Minecraft.
Basically, for me, whenever I play the game, it launches and plays smoothly without many issues, apart from small lag here and there, then after about 20-30 minutes later, the game suddenly freezes on me, unfreezing for a brief second, before freezing again and crashing completely. This has never happened before until 1.6.0.8 released.