In 2019 we were set the challenge: present a safer and more systematic method of producing the "bang-bang" test to confirm zero-volts ride-through capability. We delivered, and now, with several projects to its credit, we thought we should explain what exactly ZeroDip is, and how it improves on the original. Why do we need it? The requirement for a fault ride through test is described in the requirements of class for DP3 vessels. Testing isn't required for DP2; however, more