Tri-Direct triumphed in a three-way pitch against Manning Gottlieb OMD and Equimedia to win the brief.
The campaign, breaking in the autumn, sees the elite unit make its direct response TV advertising debut.
The DRTV will be backed by direct mail, e-mail and inserts, which direct its target audience (men aged 16 to 31) to the Royal Marines recruitment phoneline or microsite.
The inserts will run in specialist magazines to try to generate a higher quantity and quality of responses.
Marc Michaels, the director of direct and relationship marketing at COI Communications, said: "Tri-Direct was selected because the team presented a cohesive strategy, demonstrated a thorough understanding of the brief and understood the challenge of finding the right media environment to address this specific audience."
Gillian Stevens, the head of marketing at the Royal Navy, said: "Tri-Direct's strategy was felt to be the best to help us meet our objectives."