A tsunami, once stopped by a belt, will begin to stagnate. This belt is a belt of water resistance, so the belt stops the tsunami. The belt has caused the tsunami to stagnate.
While you watch the tsunami stagnate, you get ready for work. While you were watching this whole thing happening, you were tying your tie (たい). Once the tsunami stagnated, you were all done tying your tie. And since the tsunami is no longer a threat, you’re ready to go to work.