Accessing the Hatch

 is part of Vella's Storyline in Broken Age.

Inventory

 * Fishbowl
 * Yarn Arm
 * Magnetic Boot

Walkthrough
Use the Fishbowl when the spinning arm's hand is about to face you. This will give you the Yarn Arm. Do the same with the floating boot, but using the Yarn Arm. Once you grab this, you'll get the Magnetic Boot. Use the magnetized tarn arm on the mechanical arm. Then, interact with the hatch.