Structures can become detached from boats moving at high speeds, if the structure is right on the edge of the boat.
Changing line 167 in "components/walkableplatform.lua" from
if not entity.components.embarker and not self.new_objects_on_platform[entity] and not entity.entity:GetParent() == nil then
if not entity.components.embarker and not self.new_objects_on_platform[entity] and entity.entity:GetParent() == nil then
will fix this issue.
The issue is best reproduced by placing two malbatross sails on a boat, a structure on the opposite direction the boat will sail to, hoisting the masts up and running "c_save()" to cause intentional lag, which will nearly 100% of the time cause the structure to fall off (As demonstrated in the video from 0:00 to 0:35)
When the line is changed to its fixed version(in the video, I used a simple mod that replaced line 167), the issue will no longer occur (As demonstrated in the video from 2:40 to 3:16)
I don't take credit for the solution here, the bug and solution were originally provided in this bug report, I just decided to re-report it again:
See above structions