This specification supplies general characteristics and interface details of propeller type, fixed-tunnel thruster units permanently installed in marine vessels or structures. The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Note 1 -This specification supplies only general design, interface, and purchase information and does not include requirements for use, thruster controls, or associated equipment. The purchaser of the thruster equipment specified herein is cautioned that he must properly correlate the operating requirements with the thruster specified. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.