Which operation marked a significant joint action involving UDTs and Marine forces?

The assault on Peleliu is noted as a significant joint operation involving Underwater Demolition Teams (UDTs) and Marine forces. During this operation, the UDTs played a crucial role in preparing the beach for the Marine landings, which involved clearing underwater obstacles and demolishing enemy fortifications. Their efforts were aimed at ensuring that the Marines could land safely and effectively, thereby increasing the chances of success in this fierce and strategically important battle in the Pacific Theater.

Peleliu presented unique challenges due to its heavily fortified defenses, and the collaborative efforts between UDTs and Marines exemplified the synergy of naval and ground forces in World War II. The operation at Peleliu is often cited as one of the clearest representations of UDTs' essential functions in joint military operations, contributing significantly to the overall momentum of the campaign.

Though other operations, such as the invasion of Normandy, did involve extensive joint actions, the focus here is specifically on the direct participation of UDTs in the assault on Peleliu alongside Marine forces.