I personally avoid resin for all but the most thin applications. It's not possible to pour any depth without a lot of practice, patience, pracice and skill.
And you saw the statement about yellowing? It's a thing.
Bubbles are all but inevitable and can spoil hours of work.
If you want to see to the bottom of your pond, it works well to embed a piece of glass as the water surface after detailing the lake bottom, and adding texture to the surface with gel medium or even clear silicone caulk.
Bill