Shellback, formerly known as eDivo, is a free mobile app developed by the Program Executive Office for Enterprise Information Systems Sea Warrior Program. Designed to support US Naval Surface Force (SURFOR) personnel, Shellback provides an easy-to-access offline environment for accessing key information while underway.

With Shellback, Sailors can download important SURFOR information onto their portable devices, allowing them to access it without an internet connection. This app serves as a centralized location for the most relevant and current information for SURFOR Sailors. The content is regularly updated on an annual basis.

Shellback is divided into several main categories, including Admin/Training, Medical, Operations, Personnel Management, Safety, and Rules of the Road. These categories cover a wide range of topics, from correspondence and training manuals to medical readiness, ship operations, personnel management, safety resources, and maritime navigation rules.

Whether it's accessing the Correspondence Manual, learning about medical procedures, or staying up-to-date on safety-related information, Shellback provides Sailors with a comprehensive offline resource for their specific needs. It is a valuable tool for SURFOR personnel who require access to critical information while on duty.