Foreword These Guidance Notes describe suggested practice for the design@ materials@ testing@ manufacturing@ installation and maintenance of hybrid riser systems to be classed or certified by ABS. These Guidance Notes are to be used in conjunction with other Rules and Guides published by ABS as specified herein@ in particular the ABS Guide for Building and Classing Subsea Riser Systems. During the preparation of these Guidance Notes@ ABS recognized that industry participation is a vital factor both to the rapidly progressing nature of this technology@ and for the success of developing an appropriate standard which satisfies practical classification requirements. ABS appreciates the industry??s input in the development of these Guidance Notes. These Guidance Notes reflect the latest technology developments and industry practice for hybrid riser systems for deepwater installation. These Guidance Notes indicate detailed guidance for hybrid riser systems from configuration selection@ engineering design to offshore installation. This does not exclude the use of other practices for a hybrid riser system@ provided that relevant industrial design codes are followed@ sound engineering practice is implemented@ and justification for the use is adequately documented. Riser design engineers are encouraged to consult fabrication and installation specialists to establish the presence of constraints that will affect the design. These Guidance Notes become 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 these Guidance Notes is the most current. We welcome your feedback. Comments or suggestions can be sent electronically by email to rsd@eagle.org.