Hi guys,

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):

https://www.google.com/search?q=cake+waves&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=oxGxUen_FMe-igLKnICwCQ&biw=1372&bih=756&sei=phGxUaGvKKrSiwK39IDQBw

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.