You see the skill up message picking up a rock at the blockage but if building a hut it's when they hammer it in place. I haven't checked the beach yet. But to be honest I don't really trust the messages so much anymore. You get a whole lot of bogus heal ones. I tried to boost an adept to master on the blockage by picking them up after seeing the skill up but it never looked like it moved. Now true it takes alot to go to master but after 30 tries, with messages, and no movement at all I just don't trust them anymore.