An elderly visitor to Rarotonga has died while swimming in Nikao.

Police were called to the death of a 72-year-old man at the Nikao Social Centre at 12.25pm on Saturday.

"The visitor had been accompanied by friends to go snorkeling," Cook Islands Police Service spokesman Trevor Pitt said on social media.

"A medical report is expected tomorrow [Sunday]."

Cook Islands News has contacted Pitt about the result of the report.

The incident marks the third time a person has died in Rarotonga waters this year – after a 49-year-old tourist drowned in the lagoon at the Edgewater Resort and Spa in Arorangi in June, and a 52-year-old woman drowned while trying to save her 11-year-old daughter near the Arorangi jetty in January.

Meanwhile, Police were called to two alcohol-related crashes which occurred less than 15 minutes apart on Saturday night.

"Drunk driving has reared its ugly head this weekend with two crashes, followed by two arrests," Pitt said.

An 18-year-old motorcyclist was breathalysed at 980 micrograms of alcohol per litre of breath, nearly four times the legal limit of 250mcg, after coming off their bike at Black Rock at 7.25pm.

Nearly 15 minutes after the crash, a 52-year-old woman driving a car collided with a motorcyclist before hitting a post outside the Cook Islands Tourism office in Avarua. She blew 620mcg.

"Both drivers were remanded," Pitt said.