I spend at least 60-80 hours every year with this:
www.andersbq.com/2011/05/cutting-tree-is-also-about-speedsurfing.html
Do anyone in Australia do anything similar???
Yep, our course is shallow water and hidden in the weed is 2 nasty reef lines.
We have the rocky area pegged and posted, we advise people when ever they turn up about hwere it is (if they are new) or whether the tide is ok to make it safe(ish).
We still get people running the gauntlet though
Our other (more scarey) obstacle is weed and algae.
In spring we get algae so thick you can stand on it, some of it's big mats 5-8m which are easy to see.
Other clumps are about 1/2m² and just under the surface of the water these are the most dangerous ones, they are in the speed run, you can't see them till couple of mtr's away and they will stop a weed fin dead as well as everything else attached to a weed fin.
We have more (as well as serious) accidents and breakages because of weed than rocks.
We always warn people to watch out for "Birds standing on the water" or stationary white foam.
Heres a video of the "Rock garden" at low tide from the inside markers, Most of the brown stuff you see in the vid is weed.
Ya hit 19 tiny little rocks, destroy 17 fins, break 2 boards, get 14 lacerations, 12 bruises, and all of a sudden ya start gettin teased as if ya some sort of reckless fool
