This chapter outlines the historical context for the marine spatial planning (MSP) process, the plan development process and the outcomes. It explores some of the likely challenges arising for implementation of the plan. The chapter presents the 'nuts and bolts' process of attempting to form a marine spatial plan. It also presents the challenges and opportunities in working collaboratively to address the degradation of a significant marine space. The Hauraki Gulf Marine Park, established under the new legislation in 2000, took a broader approach than the earlier maritime park concept. The Sea Change Tai Timu Tai Pari project had its inception in the Hauraki Gulf Forum's 2011 State of our Gulf Report which indicated that current management approaches were not sufficient to reverse the ongoing environmental decline of the marine system. MSP is a rational and strategic approach which can be used to proactively plan for the future use of the marine environment.