Asamati is located not far from the park of Ezerani. Go down to the riverside and walking to the right you will find some towers for birdwatching.
If you walk about 500m to the left, you will find a stage to go into the water. But better not on a day the wind comes from the right. It smelled like waste water. And there was a little snake waiting under the steps of the stage. Later they told me that they are not more dangerous than a wasp, but imagine being bite as soon as touching the water. To be sure bring a stick whith you, and make the sing of the cross and a circle around it before stepping into the water.
On the photo you can notice that there is a lack of water, caused by Albania taking water out of the lake.
In other cities, they may explain you vainly from where the bus comes and where it ends, but never know about buses from other bus stations not going to the same.
But there ARE buses to the Prespa lake! It seems recommendable to plan the trip from monday to friday, because there are more buses. One of the guys selling tickets in Resen speaks English.
You will see that there is a bench for awaiting the return bus in Asamati.