Angor agreed to Erwin's suggestion because he trusted the experience provided by this professional mariner. Besides, he would also admit that Summerdew Ridge could provide the best chance of survival right now.
He was never sure if he and Toby could fully protect The Limpet from the tornado. There were many unknown parts at Devil's Water deadly to powerful wizards. It would be troublesome if The Limpet was blown off into somewhere extremely dangerous.
At least they were more familiar with Summerdew Ridge. And since The Limpet was a "frequent guest", the witch might let them pass.
In the worst-case scenario, if Summerdew decided to destroy The Limpet, Angor could still escape with Toby and grab the captain and Helen with him. Even if Summerdew was a wizard, she might not keep up with the full speed produced by the sequence of gravity.
After that, they would simply ride on Gondola and head to Ferran Land faster, with Helen and Erwin to tell the directions.
