I saw similar shots some month ago from Corrie , and i always want to try this.
Now i have test some shot. I original want a mushroom shape, but after all the xxl Shapes i don´t get them ;) I´m out of Practice with tha Basic stuff.
Such shots are very cool. But really messy. After 2-4 Pictures you need to chance the water and clean up . I´ts more cleaning action than taking photos ;)