The usage of the North Sea is in transition, influenced by the European blue growth strategy and the national follow-ups. Based on the principles of smart, sustainable and inclusive growth at sea, policies are formulated to stimulate growth in the existing and new maritime sectors. Creating blue growth will not be confined to technological change, but it will also cover changes in the human system, including ways of interacting and exchanging ideas, roles of responsibilities, as well as institutional settings of formal and informal rules. This also affects the rural hinterlands. Social innovation is needed to secure sustainable growth. Understanding the significance of social innovation is a first step to formulate governance efforts to stimulate social innovation. This chapter assesses the significance of social innovation with regards to blue growth in the North Sea. Social innovation can be explained both as process and outcome and these are strongly interwoven. The significance of social innovation – is here assessed by means of three core characteristics: scale, scope and resonance. The results show that the significance of social innovation varies considerable across the sectors; offshore wind energy, offshore mussel cultivation and offshore seaweed farming. Social innovation promises the benefit to further development of maritime sectors – just like it can benefit rural areas.