Am playing in survival mode hard in ver 1.2.
I have discovered that any boats and boats with chests that have been left in the water cannot be boarded by the player using the normal method.
A newly created boat can be placed on the water and boarded normally.
To board a previously placed boat you have to brak it with an axe and then replace it in the water. it can then be boarded normally.
Thank you for your report!
We're tracking this issue in MCPE-169772, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki