Although similar in configuration, Silver Cross' Coast and Wave strollers have some specific features that set them apart.
Overall, these strollers have really similar configurations (plus the ability to be either a single or a double stroller) and the same weight capacity. The Coast, however, is 4 pounds lighter and 1 inch shorter than Wave, and it has smaller wheels. The Wave has slightly higher quality fabrics and finishes, which gives it an elevated feel.
The Coast is lower-priced (about $300 less) and more compact than the Wave. The Coast also comes with fewer included items: its stroller seat and bassinet share the same canopy and bumper bar. In contrast, the Wave has two of everything. Another thing to note is that the Coast cannot become a double stroller right out of the box - you have to buy additional adapters to attach two seats at once. The Wave comes with those adapters in the box.