Diving Bell

Hiccup's Diving Bell is a contraption built by Hiccup in Race to the Edge, Season 4. He first uses it to dive to the sea floor to free the Submaripper by using Changewing acid to melt the chains. It is later coated with Eruptodon saliva for protection and used in an attempt to safely lower Astrid and Throk into the volcano to rescue Hiccup, Fishlegs, and Mala.