The Philippines v China Award contained a number of novel and highly progressive findings with respect to obligations for the protection of the marine environment under UNCLOS. Thus far, these elements of the decision have gone largely unexamined in the surrounding literature. This article concentrates on two specific aspects of these findings: the obligations in respect of environmental impact assessments in articles 205 and 206, and articles 197 and 123 and the duty to cooperate. It analyses the Award and identifies some concerns with the Tribunal’s reasoning in these areas. Although broadly, the Award upholds effective protections for the marine environment; this article highlights aspects of the decision in which different approaches could have been taken that would have led to stronger outcomes for the marine environment.