To reach the Isle of Man from Germany you have two crossings over the sea.
First over the channel to England and second over the irish sea to the Isle of Man. Over the channel there are some ferry companies or you go through the tunnel. To reach the Isle of Man there is only the Steam-Packet Company and this is during TT very, very expensif.
Our normal way is over Zeebrugge/Belgium to Hull and than from Hull to Heysham.
But itís your own decision which way you go and how many time you need.
Have always a safe journey!
Here are some links for ferry-companies: