The Lake
Remember the Durmstrang ship? It somehow emerged from the depths of the lake at Hogwarts. How did it do it? Could someone else do something similar?
Firstly, what exactly did the Durmstrangs do? My opinion is they went under the water near the Durmstrang Institute and somehow transferred to the Hogwarts lake.
Second, how did they do it? Is it easy to do? Could someone do it without the ship? We may never know.
Here’s the bad part: Could Voldemort get into Hogwarts in a similar manner? If he couldn’t, what if he hijacked the Durmstang ship? Are there spells that would prevent him from going through the lake? If so, Dumbledore probably lifted them only temporarily for the Triwizard Tournament (in which case, Hogwarts is most likely safe).
There are a few people that think Voldy will attack Hogwarts through the lake, and Harry will attempt to stop him. If they are wrong, we’ll never know the answers to these questions.
Here’s a new theory about how the ship works: It’s a portkey! The Durmstrangs could have turned the ship into a portkey so they could easily get to Hogwarts. Does this mean Voldy could make an illegal portkey and sneak into Hogwarts? Maybe not. There could be portkey-protection around Hogwarts. Dumbledore probably lifted the spells for the duration of the tournament. Why would he leave Hogwarts unprotected for so long? Why not just remove the spell at the beginning and end of the year? I think that portkeys maintain a magical connection, a sort of “lifeline”, with their place of origin. If Dumbledore had put the spell back in place, the ship may have returned to Durmstrang Institute — or even vanished completely — without the Durmstrang students.
