The long history of transferring older warships to allied navies

Is there a naval equivalent to one country donating older major military equipment to another?

Yes; transfers of older warships to allies and partner navies have been common, through both gifts and low-cost handovers requiring recipient-funded upgrades.

Transferring older major equipment is common in naval relationships. Britain transferred warships to the Soviet Union and supplied ships across the Commonwealth, including India, Australia, New Zealand, and Canada. Similar patterns appear in Chinese, Vietnamese, Dutch, Norwegian, Italian, and American naval relationships. American-built equipment can also pass through an allied donor, making the original supplier appear involved in more direct transfers than it conducted. Some transfers are outright gifts, while others shift the hull cheaply and leave the recipient to fund modernization. The practice converts surplus inventory into alliance support, though the receiving navy inherits operating and upgrade costs.