Jackson and I had been wanting to dive this site for a while now, however the logistics of bringing dive gear that far into a remote area in the bush had put our hopes on hold until just recently, here's the story...
Opened in 1909 and decommissioned in 1916, the Long Lake Gold mine had a short lifespan compared to the many other mines in the Sudbury area. Like many other open pit mines that where abandoned, it eventually flooded. 95 years later, the only things remaining from the original site are a few cement foundations and of course, the open pit.
My day started bright and early and with a quick stop at Timmies, I was to meet Jackson at his place. Although the only ones diving would be Jackson and I, there was 6 of us going out to the site. The others, not really having any interest in diving, were going to explore the old foundations.
The gear was to be transported to the site with the use of John's Samurai. I'll say this, although this truck was quite small it served it's purpose perfectly. Loaded with all the gear needed for two guys to do a dive, Al and John drove off to go drop of the gear. In the meantime, the rest of us jumped into an aluminum boat and took off. We where to meet John and Al at the end of Long Lake where they would pick us up and bring us to the site.
We had to be creative with all the transportation because the samurai wasn't exactly "road worthy".
Once on site we setup and jumped in.
The open pit couldn't be accessed directly because of it's 30ft cliffs all around the perimeter. Apparently however, the pit could be accessed via a small 15x15 foot pool located about 50ft to the north. Not really knowing if this pool actually had a tunnel connecting to the main pit, let alone whether it was still accessible, Jackson and I jumped into the small pool and headed down. 5 minutes later we surfaced again with smiles from ear to ear, success. 
There was in-fact a tunnel located about 40ft down into the pool. The passage was quite large, having about a 6 foot diameter. We told everyone the good news on surface and headed down again, however this time we were pushing thru.
Before heading in, I took a minute to tie off a line and off we went. About 15ft in, we turned a slight bend and wouldn't you know it, there was a light at the end of the tunnel! This tunnel was around 70ft long and near the end it forked into two, both forks ended into the open pit. Once at the end, I tied off the spool and we started heading up to tell the others the good news.
The remainder of the dive was spend exploring the open pit itself. I'm sure this water was a little on the acidic side because I've never seen water that clear. The open pit has a diameter of around 165ft, and the visibility seemed to improve the deeper we went. At the 100ft mark I could see Jackson clear as day, he was on the opposite side of the pit...165ft away. Amazing.
We continued to explore, not wanting to go much deeper then 100ft because of a white "cloud" on the bottom. After about an hour we were going thru the tunnel again and a few minutes later, back on surface.
I did actually see signs on life in the pit, a little water bug swimming around. Unfortunately I wasn't able to take underwater pictures because I forgot my camera in Victoria, bummer. Edit: The white could we encountered was actually a layer of hydrogen sulfide. Normally this is found in caves or deep pits. Luckily it isn't much of a concern for divers as long as you don't ingest any of it. It will however leave you with a rotten egg smell when you surface.
Here's a picture I found on the internet of what it looks like.