I'm trying to achieve a wavy/ocean look through the use of buttercream. I saw this cake on Pinterest (credit to Simply Sweet Designs) that I really like. Can anyone give some advice as to how to achieve this look, or something similar using buttercream? Thanks :)
Lots of wavy cakes out there (of course a lot of them are fondant, but not all):
The picture you provided is not really 'waves' but ruffles:) It looks like the decor4ator used tip 87 and just piped zigzag lines around the cake. A similar look can be done using tip 102, 103 or 104.