Final answer:
The most common methods for underway-connected replenishment of missile transfer today are Vertical Replenishment (VERTREP) and Conventional Replenishment (CONREP), which are used together to efficiently resupply naval vessels.
Step-by-step explanation:
The most common method for underway-connected replenishment (UNREP-CONREP) for missile transfer today is a combination of Vertical Replenishment (VERTREP) and Conventional Replenishment (CONREP). These two methods work together to provide a versatile and efficient means of resupplying naval vessels with missiles and other cargo while at sea. VERTREP involves the use of helicopters to transfer payloads from the supply ship to the receiving ship. On the other hand, CONREP involves the use of lines and rigs to transfer items directly between two ships. The combination of these methods allows for the transfer of a wide variety of cargo types under different sea conditions.