There’s probably not much to worry about snake-wise on Roatan, especially compared to mainland Honduras, however, there is the Roatan Coral Snake (Micrurus ruatanus) but it’s rarely seen, endangered, and has no verified records of death that I am aware of. Be aware though, that some locals claim it isn’t poisonous, but it is. See The Amphibians & Reptiles of the Bay Islands And Cayos Cochinos, Honduras. (We are Amazon Affiliates.)
There is also a non-verified report of the pit viper (fer-de-lance) on Roatan.
Here’s some info from http://www.coralsnake.net/micrurus/roatan-coral-snake.html:
Family: Elapidae (fixed front- fang venomous snakes)
Other common names: Roatan coral snake, coralillo, coral de la Isla de Roatan, coral roatanense, lim lin, silbara
Small, fairly slender, 2 colored coral snake, adults usually 50 to 60 cm long (max. 68+ cm). Body with alternating 33 to 45 black and dark red rings; black rings may each vary in width. This is the only coral snake (or ring patterned snake) on Isla de Roatan (in the Departmento de Islas de Bahia of Honduras). Probably closely related to the mainland species M. nigrocinctus.
Honduras (restricted to the Bay Island = Islas de la Bahia, Roatan Island)
Found in tropical moist forest on the north and south sides of Isla de Roatan, which is about 65 km off the north coast of Honduras. Occurs from near sea level to nearly the highest point on the island (235 m elevation).
Mostly nocturnal (and maybe crepuscular), terrestrial (probably also burrows in loose sandy soil or vegetative litter), and reportedly very secretive. Not aggressive, and seldom reported to bite humans, even when handled. Probably oviparous (clutch size not reported, but probably less than 15 eggs). Probabaly preys mainly on local lizards, amphibians, other snakes, and invertebrates.
Not much known… …Venom of most coral snakes is mainly potently neurotoxic. Reported bites to humans have usually been on a toe or finger and occurred during the victim’s attempt to catch or handle the snake. No well documented serious envenomations nor fatalities of humans due to bites by this species, so far.