High Dives
From WikiRaider
A High Dive is a special platform in Rise of the Tomb Raider and Shadow of the Tomb Raider where Lara can perform a Swan Dive in order to complete the respective High Diving Challenges in the games.
In Rise of the Tomb Raider these platforms are made from wood and the edge is marked with red paint, while in Shadow of the Tomb Raider they seem to have no special markings on them.