Remember that if you have it in a taller pot the plant will be at a depth less than that. I also put hollow concrete blocks under pots to bring the plants closer to the surface. If the water is clear and in a good sunny position the lily would probably survive, but better if you could raise it up off the bottom.

I don’t fancy the idea of getting into the pond haha.

its in full sun for 9 hours of the day. And the water is clear. Hopefully it’ll be ok?

i might just lower the pot gradually - have it hanging over the pond on a big stick , on string. That’s an idea, just to get it established? I could lower it a few inches every week till it reaches the ground? What do you think?

Thanks

I think that's a good approach. But I'd wait until some leaves are approaching the surface before putting it lower. Getting the stronger sunlight will encourage it to put up more leaves. I have a different species (N. violacea) that are growing in just over 2 metres of water. They're in too much shade but they still grow. Only thing is growth is a bit weak and the flowers a bit smaller than usual. But most of that is the result of too much shade.