Hi Martin,
The hull on the multi dates back to the 2006 vintage. The Surf60 shares the same hull as the multi if it was built since 2006, but will have the older hull shape if it was built pre-2006. My understanding is that Red7 have effectively replaced the Surf60 with the Multi. The multi has been so named because its pretty effective on rivers or small surf. The hull is super stable (which was the no.1 priority with the boat), but also pretty quick considering its length (5.8m). The footwell has been adapted to accommodate an extreme range of paddler from small kids to 6'8" individuals. So really cool as a family or club boat. Also, there are various rudder options apparantly to suite river or surf. Hope that helps.
Cheers
Dave