Stefan and I were discussing this and he asked that I get some drawings made up and a poll on the forum to ask how people felt about the proposed pieces so that he could discuss it with Nate; the idea would be to add these packs during the pledge manager so that we could buy them as part of the KS6 caverns kickstarter.
Here are picture so the proposed sets, along with the existing KS2 water pack.

And here is an example of what you can do with them mixed with KS2 water tiles. You will note that I left a few sections in just using KS2 pieces to show you how " square" they are in comparison to the organic nature of the new pieces.

Pack make up and pricing would be similar to the current KS2 water tile pack, leaving it up to DF to do what is best. But, probably like 4-6 of each sculpt in each pack.
Obviously, we would expect a slight mark-up in price since KS2.
So, what we need is for people to "vote with their wallets" shall we say. I have included an option for "I am not interested" so that it isn't too lopsided and biased of a poll.
Please vote and get your DF collecting friends to vote. Also, feel free to post how many sets you'll buy if the poll doesn't represent you well. I know a number of us have stated that we will buy 10+ of each set, but the poll only allows so many options.
NOW is when DF is listening. IF YOU WANT MORE WATER TILES, NOW IS THE TIME TO VOTE AND POST. I'll send this link to Stefan in a few days.