Those can be good waters but the rivers and waters near San Martin de los Andes are the beaten path of Patagonia. The whole area is more developed than further south.
If you ever have the chance to go again visit Los Alerces in Chubut province (you should have a contact with a boat, though). There's no comparison and you'll be walking along 2000 year old trees in some areas that will make you feel very small.
Fish the Rivadavia, Menendez and Futalaufquen Rivers. Fish Lago Verde, Futalaufquen, and Menendez lakes (the latter on a windless day), and you will be amazed.
Have a barbecue on the shores of Lago Cholila and drnk some wonderful Malbecs and cabernets (my cabin fever is a a maximum right now)