Nuh, they're running on wheels.
The controversy was about using ground effect to increase the lift of a planning craft.
Water is just going to slow these guys down.

No it's not worth getting worked up over, but I feel that speed sailing is splitting into two distinct categories. As different as Formula is from slalom and wave sailing from freestyle maybe?

The 250 to 300 mm barrier has been passed. Delta speed fins are down to 17cm. The 55 degree rake allows it to skim the sand without kicking off the rider.

According to freestylers, the ground effect in this much water noticeably effects the ease of doing sliding manouvres.

Theoretically you only need adequate water to throw sideways to oppose the sail reaction. Shorter multifins will scavenge enough water to do this in even shallower weed banks. The multiple end effect may not be all that bad skimming close to the sand.

I'm not saying it's a bad thing, I spend plenty of time skimming the weed beds. It's a challenge in a different sort of way. I'm sure I can feel the drag drop off as the water depth reduces, the chop disappears - and the bank looms closer! But it's a distinct category of sailing. I'd class Sandy Point as open water Sailquick, that rolling chop as you get to top speed is another thing altogether. Sandy Point has no uniformly shallow regions that can be used for the purpose. But yes defining the boundary between the two categories would not be easy. Which is probably why it won't be done.

The depth of Lake George is a bit like how long is a bit of string.
Very shallow on the edges to a couple of feet deep in the middle when I was there. The weed varies in depth from the surface as well. Maybe from 20cm to right on the surface.

Trying for Nautical miles, I ran aground approaching the spit that separates the big lake from Middle Lake. The bottom was hard and it stopped me quick! In other places it was hard to tell if you were dragging the fin in soft mud or if it was just thick weed. Both significantly retarded speed though.

I would say that in the best parts of the lake (last January) for speed, it was at least 50-60cm deep, many places it was close to 1m. But when you tried to stand up you sunk to your shins in the mud which left you waist to chest deep.

Well

I'll start with I am a FOOL!

One day I was desperate for a sail at Lucky Bay, there is a sand bar about 4 to 500 meters out, it was low tide actually very low tide, nice wind and bugger all windsurfers about! Obvious reason for that, anyway I rigged up and went out for a blat, I was comfy powered up not ballistic just comfy, I went across the sand bar with the fin just racking the shells but I noticed that as the water became very shallow everything seemed lighter, I got past the the sand bar went out to the second or 3rd marker turned (Dropped the rig and water started type of turn, the only one I know how to do) came back towards the bank with more speed and very committed, sadly without the same luck as I had getting out, long story short, I crashed. But before the crash again everything seemed to feel lighter for the solid run I had before the fin grabbed the sand and minced me, the mast, a sail, a boom and cracked the nose of the board, yes I deserved that but did I feel ground effect? I think I may have.

Remember I am a very average at best sailor, just thought I would share my story.

Cheers.

I normally use a 33cm weedy down there.