Until just a few years ago, the Totora boats were used by islanders as a way of transport. Because these boat didnt last long, they changed to modern boats.
The bigger ferry boats could even handle small buses. In fact, I even saw bigger buses than these go across. There was even a pickup with a cow in the back on one ferry.
Many locals have fishing boats for a livelyhood as well as getting themselves and I imagine tourists from point A to B on the island. Other than that, you pretty much have to hoof it!
With no cars on the island, you pretty much have to walk around the island but locals use pack animals to bring goods from the ports up to their hillside domiciles.
Copacabana is placed almost in Peru, on a peninsula of peruvian territory. That´s why you have to cross the Titicaca to go there if you don´t want to go the long way passing by Peru.
You have to pass the lake Titicaca to reach Copacabana. Therefore you leave the bus and go by motorboat while the busses are carried by little wood ships as you see in the picture. Awsome.