There’s great snorkeling all around the Cayos Cochinos [1], but visitors should bring their own gear, as well as fresh drinking water and a few other supplies like fruit or crackers. Prices vary, but usually a boat from Nuevo Armenia or Sambo Creek [2] should do the trip for US$150–200 (per boat, not per person), or less, depending on your negotiating skills and perceived financial status.
A variety of one-day cruises to the Cayos Cochinos, normally visiting Chachahuate [3] with stops for snorkeling, can be arranged in Roatán [4] and Utila [5], often for around US$50–70 per person, depending on how many people go; it’s extra to bring scuba gear along. It’s also possible to arrange trips with one of the tour companies in La Ceiba [6].
Links:
[1] http://www.moon.com/destinations/honduras/the-bay-islands/cayos-cochinos
[2] http://www.moon.com/destinations/honduras/the-north-coast/la-ceiba/east-la-ceiba/sambo-creek
[3] http://www.moon.com/destinations/honduras/the-bay-islands/cayos-cochinos/chachahuate
[4] http://www.moon.com/destinations/honduras/the-bay-islands/roatan
[5] http://www.moon.com/destinations/honduras/the-bay-islands/utila
[6] http://www.moon.com/destinations/honduras/the-north-coast/la-ceiba