Guild Wars 2

Can someone tell me how to get to that poi in silverwaste?
Must I do the jumping puzzle to get there?

Short answer…Yes

The POI is not at the end of the puzzle, so you can fall and land on it without finishing the puzzle. But you have do about 75% of the puzzle to get the spot to fall (and die ).

Don’t have to do JP at all.
Get on the skritt ship. South of it is the beginning of the JP. Get to a point where a flag pops out of the hole and skritt kit starts talking to you. That gives you [Milestone] buff. Now you can get ressed by skritts if you die in the cave.
Now jump down the cliff into the void below the ship. You will get revived and can run through the cave to POI with no trouble.