my dream is making soaps like the one attached, basically with regular soap for the sand, moulded soap for the shells and clear soap tinted blue for the water.
As it happens, some of the first soaps (2005) I ever made were transparent (i.e., NOT "translucent") soaps. You could clearly read 12 pt. font through them. The technique involves making CP (cold process) soap then adding a "polyol" mix of 150-190 proof grain alcohol (NOT isopropyl alcohol) aka, "Everclear", glycerin & simple sugar syrup to clarify. Beautiful soaps but
cost twice as much to make from scratch than basic CP soap. I do not make them any more for that reason.
I apologize for the quality of the pictures. They were taken 16 years ago.
To duplicate the soap in the pictures, I would learn to make clear M&P (Melt & Pour) for the top, opaque M&P for the bottom and the shell embeds. You should be able to find molds online for the embeds and rectangle single cavity molds for the soaps. All for far less expense than making all 3 from scratch.
There aren't many M&P soapers on this forum, but you'll need an expert instructor to help you to create your dream soap. Hopefully, if you have a local crafters shop like Hobby Lobby in AU, they can refer you to someone. They can also supply you with a starter kit, although eventually you will want to purchase the best M&P available. For basic instructions, both
Bramble Berry and
WSP (Wholesale Supplies Plus) here in the States have tutorials for making M&P.
ETA:
Free Beginner's Guide to Melt & Pour Soap
Seascape M&P Soap
GOOD LUCK & HAPPY SOAPING!