What is the purpose of a frog in naval terminology?

In naval terminology, a frog refers specifically to a device that holds a sword or sabre in place on a naval officer's or marine's belt. This attachment ensures that the sword can be drawn swiftly when needed while remaining secure during movement. The design of the frog typically includes a loop or series of loops that allows the sword's hilt or frog to fit snugly, thus providing easy access while maintaining proper military appearance.

The other options refer to different concepts in naval operations. For instance, stabilizing a ship during rough waters relates to the use of ballast or stabilization systems, not a specific item like a frog. Signal flags serve various communication purposes at sea, while a safe landing area typically pertains to aviation or landing operations rather than a decorative or functional item worn by personnel. Each of these concepts exists within the broader context of naval practices but does not pertain directly to the role of a frog in holding a sword.