To (a) (task 2.5) analyse scour development around offshore GBS to optimise design scour procedures. Foundation scour is well established in bridge engineering, where scour depth is linked to the diameter/width of structural elements. This translates to offshore monopiles and jackets relatively easily, but leads to over-estimation in scour for GBS, which have variable cross-sections. This task will include computational fluid dynamic analyses to develop a scour design approach for GBS systems with varying sections and scaled model tests. (b) (task 2.6) to develop an optimisation model for GBS scour protection, optimised to the scour conditions established in task 1.5. Focus on material optimisation and type (rock-armour, concrete mattresses, synthetic weeds) and pre-installation requirements prior to deployment.