Paraty is on the Costa Verde about 5 hours south of Rio by bus. It was the original port that the road up to the gold fields went from, so was an important town in its day. The historic centre has been preserved and it's all cobblestones with a pedestrianised main street. It's also the most expensive place I've been to in Brazil. Prices are not much better than the UK for food and drink.
There are a lot of islands off the coast there and a number of dive shops in the town. There are also a lot of places selling dive t-shirts which seem to mostly feature sharks. I booked a day's diving with Adrenalina. The price was R$180 for a day including all equipment, which I thought wasn't a bad. I was told to get the bus marked Trindade and tell the driver I wanted to get off at Marina Farol De Paraty. I actually told the conductor this, sat next to him and he told me when my stop was coming up. If I hadn't we would have sailed past it as the bus stopped before the entrance, before I'd seen the big stone outside and way before any signs. Brazilian bus drivers often seem to think they're Ayrton Senna.
There were three boats by the dock and we were taking one of the two big ones. There were a lot of snorkellers and people doing try dives on board. Only a couple of people had their own kit. Everyone else, including me, was using rental, which was of reasonable quality.
The wetsuits we were using were 5mm one piece. The guy tried to give me a 12kg weightbelt. I got him to reduce that to 10kg, though really 8 would have been enough. The diving wasn't difficult or deep. We sailed out to one of the smaller islands and did a couple of dive. The underwater topology is big granite rocks and a sandy bottom. There's a lot of coral growth in the top 5m, with brain corals and small sea fans. Below that, there isn't.
January is the wet season and it had been raining for at least a week, so I wasn't expecting great things of the visibility. It turned out to be 8m, though it often looked worse than that. The top 6m or so was 27C, then there was a thermocline. My computer never registered less than 26C but the sensors are quite slow to react. It was definitely less than that. I'd guess about 23C. When the two layers of water get mixed up, it gives the water an oily quality which reduces the visibility further. If you've never seen it before, it's a bit of a novelty. The sandy bottom was made up of fairly coarse sand which I thought would have been quite hard to kick up, but several of the other divers proved me wrong on that front.
The first dive was to just under 10m. As well as the rocks and coral, there was also the wreck of a plane and a statue of Jesus, which was covered in corals. Fish life was reasonable with damsel fish, sargeant majors, midnight majors, some species of butterfly fish, a leatherjacket and flying gurnards. Some of the rest of the group also saw a stingray.
The second dive was 8m and the fish life was much the same. There were a couple of swim throughs and there were bullseyes hiding in the dark in them. I also saw a big cow fish and a couple of big angel fish.
Lunch was provided on the boat in the form of hot dogs, fruits and sweets. There was plenty of water and Coca Cola. It was a good day out. The diving wasn't great by any means, but it was nice to get into some warmish water, though after a couple of hours of constantly going up and down through that thermocline, it didn't half feel cold on the bottom.
The heavens opened on the way back in, but there was room in the cabin for everyone and it had more or less stopped when we got to the marina. Heading into town, there's a covered bus stop outside, so getting back to my pousada was easy. I actually got a mini-bus which charged then same R$3.70 as the regular bus.
Paraty is well worth giving a look for a couple of days. It's a nice place to spend some time. There isn't a beach in town, it's all mangroves, but there are plenty nearby and the buses are regular and cheap. Mozzie repellant is a good idea though.