Foreword (1 February 2018) This Guide for Nondestructive Inspection of Hull Welds was originally published in 1975 and subsequently updated in 1986@ 2002@ 2011@ and 2017. This Guide introduces details of inspection criteria and inspection techniques@ which are considered as being widely recognized by the industry as a reliable means of inspection of structure members and their welds during the construction of surface vessels and other related marine and offshore structures. The 2017 edition incorporated a new Section 4 with criteria for Phased Array Ultrasonic Testing (PAUT). PAUT has become a common nondestructive testing method in use in shipyards for marine and offshore structures across the world@ as it provides quicker examination than conventional UT technique for complex geometries. The February 2018 edition incorporates a new Section 5 for Time of Flight Diffraction (TOFD) ultrasonic inspection. The TOFD ultrasonic examination technique can provide improved detection and sizing capabilities of discontinuities compared to standard ultrasonic pulse-echo techniques. Both PAUT and TOFD produce a permanent record of the inspection in electronic format. It is intended that this Guide is continually published as a Guide@ rather than Rules@ in order to collect more feedback from industry during its use and be able to reflect this feedback back into the Guide in a timely manner. Upon completion of this further calibration period@ the Guide is to be published as the Rules for Nondestructive Inspection of Hull Welds. This Guide becomes effective on the first day of the month of publication. Users are advised to check periodically on the ABS website www.eagle.org to verify that this version of this Guide is the most current. We welcome your feedback. Comments or suggestions can be sent electronically by email to rsd@eagle.org.