Vaquita marina, a small species of porpoise endemic to the Northern Gulf of California in Mexico, is the world’s most endangered cetacean species. With the purpose of preserving vaquita, the Mexican government launched PACE-Vaquita in 2008. PACE-Vaquita compensates for temporary reductions in the fishing effort; as in a program to accelerate technology adoption, PACE-Vaquita compensates for switching to vaquita-safe fishing methods; and as in a buyback program, PACE-Vaquita compensates fishermen for a permanent exit from fisheries. This paper seeks the factors explaining fishermen’s participation in PACE- Vaquita. This paper shows that fishermen with skills in alternative economic activities are more likely quit fishing, and fishermen with relatively less productive vessels are more likely to switch to vaquita-safe fishing methods.