It should make for quite a splash!
The 10,000-tonne hull of the UK's new polar ship will be put in the River Mersey later - around 12:20 BST.
Named after the TV naturalist Sir David Attenborough, the vessel has been assembled at the Cammell Laird yard in Birkenhead and placed on its slipway.
The broadcaster himself will be asked to unleash his steel namesake - pushing the button that sends the hull sliding down wooden rails which have been caked in thick grease.
The hull will go in stern-first and should create a big wave as it bites the water just as the Mersey reaches high tide.
To read more on this visit:https://www.bbc.co.uk/news/science-environment-44828136