In a document titled the Wellington Declaration issued after their fourth in-person summit in President Joe Biden's hometown Wellington in Delaware state, they also expressed concern "over recent dangerous and aggressive actions in the maritime domain", a reference to ongoing Chinese aggressive behaviour in the South China Sea.

The newly announced cooperation between the coast guards will be marked by the first-ever Quad-at-Sea Ship Observer Mission in 2025 to "improve interoperability and advance maritime safety, and continuing with further missions in future years across the Indo-Pacific".

The leaders of the four nations also announced the launch of a new regional Maritime Initiative for Training in the Indo-Pacific (MAITRI), "to enable our partners in the region to maximize tools provided through IPMDA and other Quad partner initiatives, to monitor and secure their waters, enforce their laws, and deter unlawful behaviour". India will host the inaugural MAITRI workshop in 2025.

They also launched a Quad maritime legal dialogue to "support efforts to uphold the rules-based maritime order in the Indo-Pacific. In addition, Quad partners intend to layer new technology and data into IPMDA over the coming year, to continue to deliver cutting-edge capability and information to the region".

Yet another new initiative on maritime security was a Quad Indo-Pacific Logistics Network pilot project, to "pursue shared airlift capacity among our nations and leverage our collective logistics strengths, in order to support civilian response to natural disasters more rapidly and efficiently across the Indo-Pacific region".

The four leaders also committed their governments to the Quad Cancer Moonshot that will initially target cervical cancer. India will provide testing kits worth $7.5 million and technical assistance. Other countries announced their own contributions.

Cancer cure has been a personal ambition of US President Joe Biden who lost his eldest son to brain cancer. He led a White House initiative called the Cancer Moonshot programme as Vice President to President Barack Obama and as President himself.

The leaders also cleared the expansion of ongoing initiatives on infrastructure, emerging technologies, climate and clean energy, cyber, space and people-to-people engagements.