My reason for developing this fear

Story time kiddies. Just typing this gives me goosebumps ha haI developed this fear when I was up in Muskoka (Ontario, Canada). As background, we had a swimming platform to swim out to which is anchored to the bottom during the summer months and brought in during the winter. So, this platform is floating about 20-30 meters out into the lake, so not too far. I swam out with a few more people and all was good.The ladder felt slimy but didn't bug me (keep in mind that the water of the lakes in and around the Canadian shield are very murky due to all the pine trees, like dark tea!) While standing on the ladder I couldn't see my feet which kinda bothered me, but it wasn't a huge deal.We spent some time screwing around and pushing each other off of the platform and just having a good time. Everyone decided that it would be a good idea to see who could touch the bottom. (you know where this is going) Apparently, I was the only asshole who didn't bring goggles, but not wanting to seem "lame" I went ahead and jumped. You have to understand that these lakes drop off quickly and are extremely rocky (and dark!). Diving in, it was cold and murky but I kept my eyes closed. After what felt like an eternity (only a few seconds) I touched bottom, hitting it with some speed my arm went into this half meter thick mat of "stuff". That scared the hell out of me, so I tried to push off of the bottom through the cold mat and get to the surface. On my return to the top I had misjudged where I was going, so I ended up scraping my side on the massive, slimy, cold chain. Of course, I also hit the underside of the platform which felt rotten and disgusting. I noped the fuck out of there and remained on the shore for the remainder of our trip. Keep in mind that although this is very detailed, this happened in only 20 seconds or so. So that was my experience, luckily I had my tetanus shot! Feel free to share your experiences too.Also, I have some GoPro footage of the bottom of the lake that we took by tying a flashlight and our GoPro to a fishing line and rod. I can post it if anyone wants to see it.