Kiwi conservationist Pete Bethune has walked out of a hospital in Costa Rica after a deadly snakebite almost claimed his life two weeks ago.

He was bitten by the highly venomous Fer De Lance snake in a South American jungle just after Christmas.

Initially fearing he would not make it out alive, Bethune managed a difficult three-hour trek, clambering and dragging himself through unforgiving terrain to reach his boat.

Bethune told Tim Dower he is one happy camper to be alive and back on his ship.

"I gave myself a bit of a fright... when I first got bitten I thought I was a dead man, we were so far from being able to get out of that jungle in terms of distance. I know the history of the Fer De Lance snake - some people are dead in five minutes, some it might take four or five hours."

By the time he got to a hospital, his left leg had swollen to at least double the size of his right after the viper sank its fangs into his lower calf.

Bethune says there are ongoing issues, which include a bladder problem and muscle issue on his calf. However medical professionals expect both to clear up soon.