From Worms Knowledge Base
ReplayShark is a program that allows you to "capture" any given moment during a game, allowing you to build a directory of replays each labelled with a timestamp indicating the time something interesting happened in that replay. Simply put, it is a convenience program which eliminates the hassle of manually going through the replay after your game and finding the interesting turn, and then copying the replay and adding a timestamp. ReplayShark does this all for you at the press of a hotkey (specifically, Ctrl + F12).
ReplayShark requires WormKit to work.