This document discusses experimental approaches for developing underwater concrete formulations. It begins with an introduction to underwater concreting and a literature review showing limited recent work in this area. It then outlines 15 experimental concrete mixes containing ordinary Portland cement, superplasticizers, mineral admixtures, and various natural and synthetic viscosity-enhancing admixtures. The document discusses the properties required for underwater concrete, including flowability, bleed resistance, and strength development. It also reviews methods for testing underwater concrete, including washout resistance. The goal of the experiments is to identify admixtures that provide effective washout resistance at low cost using available natural materials.