Today has been great day’s work, one of those days that makes putting together a campaign like this worthwhile. We discovered a reef of polychaete worms of the Sabellaria cf. spinulosa species at Brown Bank, in the westernmost part of the Dutch waters. We conducted an 80-minute ROV on the seabed to film the reefs that these little builders have made by cementing tubes together to create reefs up to 30 centimeters tall that cover several square meters. We were in this same region but a bit more north during our 2016 campaign, where we found small aggregations of these worms. This time, however, we found already significant reef extensions protected by international law, as they are essential for other marine species that use these reefs for protection and feeding and are, unfortunately, very sensitive to certain fishing gear. Finding and documenting this protected habitat is the reward for all the hard work and effort of the dozens of people who participate on this expedition, either on board or from the office.