Why amphibious mobility is more than flying troops to a base

Does the Royal Navy still retain its hovercraft capability, or would it need to retrial and recertify it?

The Royal Marines still have small hovercraft, but the larger concern is preserving amphibious shipping that can deploy troops where events require rather than only where bases already exist.

The Royal Marines are said to retain small hovercraft, while the wider discussion concerns the loss of amphibious lift. Flying troops to pre-positioned equipment depends on intact airfields, surviving stockpiles, and a destination chosen in advance. Amphibious shipping lets commanders choose among Norway, Iceland, Greenland, Denmark, the Falklands, or another coast as circumstances change. The airfield problem also has a historical example: destroying airfields was a Royal Air Force mission during the Cold War.