For casting under and in water
To ensure a satisfactory end result, forms should be relatively tight and the water stationary. When the water is flowing, there is a risk of leaching and separation, if that is the case, an anti-leaching agent should be added (provided by suppliers of additives, leaching admixture).
It is best when the material is pumped into a form, the hose should be immersed in the mortar at all times and pumped from the bottom, ensure that water present has a way out of the form. As the mortar is heavier than the water, the water is pressed out of the form when the mortar is added. An especially suitable material for pumping in and under water is Bemix S3. which is fibre-reinforced and sticks together well.
Read more about Bemix S3.