Home NI621 Guidelines for moonpool assessment NI621 provides guidance for structural assessment of any vessel fitted with a moonpool (drilling ship, offshore service vessel, floating offshore unit, scientific vessel). ReferenceTitleEditionNI621 R00Guidelines for moonpool assessmentJan 2016check related documents:NR569 Classification of drilling shipsNR467 Rules for the classification of steel shipsNR445 Rules for the classification of offshore unitsCheck other Bureau Veritas rules and guidelines.