An external payload module or body that is mechanically attached to the exterior of a standard production AUV. The module expands the applications for which the AUV can be utilized and/or enhances an existing application(s), enabling current single or limited use AUV's to have multi-mission capability or enhancing existing capability without requiring complete redesign of the AUV. This approach capitalizes on the advantages of high-volume small AUV production to maintain low manufacturing and handling costs, while enabling greatly improved AUV mission flexibility.