An American surfer was in serious but stable condition after being attacked by a large crocodile at a popular tourist beach in Costa Rica last week.
The man's friend was credited with saving his life after fighting off the reptile with his bare hands.
Pat McNulty, a lifeguard in Tamarindo, a northwestern town favoured by surfers and eco-tourists, said the man was crossing a river with the friend when the crocodile struck.
"It was a vicious attack and he was bitten several times in the leg as well as the head," Mr McNulty said. "They were able to get him free, swim him to safety and then trained lifeguards responded and we administered first aid and called an ambulance."
Mr McNulty said he accompanied the victim, who remained conscious after the attack, to Liberia, the provincial capital, where he underwent surgery. He said the man had suffered lower leg trauma and described his condition as serious but stable.
"His friend saved his life and then we the lifeguards helped keep him alive," Mr McNulty said. "It was a very traumatic scene and all individuals attending him did a tremendous job."
Local media reported that the victim suffered partial amputation of his right ankle.
Mr McNulty said he knew the victim, who is a surfer from Colorado who has a residence in the town, but declined to identify him.
Family members were travelling to be with him, he added.
The US Embassy in Costa Rica said it was aware of the case but declined to comment further, citing privacy considerations.
After the attack, community, wildlife and tourism officials met to consider strategies for relocating crocodiles and making sure there was proper signage to keep people safe.
A few months ago, there was a "minor incident" in which a smaller crocodile bit a person, said Mr McNulty.
"We live in a country where there's large crocodiles and people take for granted that when you go into a river that you're safe," the lifeguard said. "But the fact of the matter is that you need to be aware of your environment. We're in their world."