Hi, I'm from Argentina. Your are welcomed to our country.
Though Puerto Madryn is a city frequently visited by foreign people, you will find only seldom locals speaking english.
There are a lot of dive operators in Puerto Madryn. Some good, some, well, not.
If I had to select an operator to dive there I would choose
Scuba Duba
Another one to recommend could be
Abramar Buceo. Both of them are located in the coastal avenue in the south part of the city.
With respect to places to dive, there are several.
To begin with wrecks, you can dive 4, Albatros, Miralles (two big fishing ships), Folias, a fishing ship laying semi-submerged near the coast and a new one, recently sunken, Urabain, an ilegal chinese fishing ship recently captured by the naval Police.
There are also several underwater parks, like "Parque Piedras" and "Lobería Punta Lomas" where you can dive with friendly sea lions (Lobos marinos).
Near Puerto Madryn, something like 100 kilometers away, is Puerto Piramides. It's a small coastal village with excellent diving also. This town is the home of whale watching boats.
Water temperature calls for drysuit year round. You can rent a drysuit with the operator, but also in
PINOSUB. You will need to reserve your drysuit with time, because it could be hard to get one without a reservation. 7 + 7 mm wetsuit could also be used if you are resistant to cold, it fits perfect and the weather outside is warm. You will need also a hood, boots and gloves. These last 3 items will be hard to rent and you will need to carry them (but the boots) if you dive dry or buy locally.
Visibility is normally good, in the order of 6 to 12 meters, sometimes better, sometimes worst.
Wind is a point to consider. Sometimes all activity is suspended owing to the wind. In those cases, normally the following day you will be able to dive but visibility will be reduced. Those windy days you can visit several interesting places, like "Punta Ninfas" where you can visit a sea lion group (Lobería) without proximity restrictions, "Playa El Doradillo" where you will be able to see whales from the coast or the "Eco Centro" a wonderful museum of the sea and marine life.
The average price for the dives is like any other part of the world. It could range 120 US dollars per 2 tank on board excursion. Sea Lions dive is far much more expensive, but it's the gold star of the city.
It will be hard to find prices in the web pages of the dive operators. Our currency is "pesos" and we are having a lot of inflation, so prices in pesos change every day.
A good dive center should ask your divelog and dive C-card. If you are not diving since a lot of time, take a refresher course and give no chance to be refused. Discussing if you do not speak spanish, could be a pain (there, just there).
I hope you enjoy our coast and the beautiful city of Puerto Madryn. If you have any other question, just ask here or PM me directly.
