Which piping nozzle for sea-wave butter icing?

[SkepticalCat]

I'm not sure if this is the right topic (didn't there used to be a cakes & bakes topic?)

Anyway, I'm making a birthday cake for DD later this week and she has requested an "under the sea" theme. I have bought some sea-related decorations (starfish, seahorses, fish etc), and am planning to pipe butter icing (coloured blue) to look like waves.

Which nozzle will be best?

I have nozzle numbers: 2, 4, 24, 27, 30, 59, 61, 67, 98 and 104.

Usually I just stick with nozzle no. 30 and do simple flower rosettes.

I'm thinking either no. 30, but doing a swirl, or no. 98, perhaps?

YouTube is your friend here - googled "sea icing" and this one was top...

Ah, thank you, that's amazing. Not sure if I'll be able to recreate, but I'll give it a go!

It says in the comments they used a 1M nozzle to achieve this look, which I don't have, but I'll see what I've got that's similar.