Five men involved in a plot to bring cocaine with a street value of £112m to the UK from South America in a sailing catamaran have been jailed.

The 1.4 tonnes of cocaine was found in the vessel, SY Nomad, off the Cornish coast by a Border Force cutter and escorted into the fishing port of Newlyn.

UK nationals Nigel Clark, 64, and Dean Waters, 59, who were living in Spain, Raymond Dijkstra, 27, from Holland, Estonian Richard Must, 49, and 21-year-old Latvian Voldemars Gailis received sentences ranging between 16 and 30 years imprisonment at Bristol crown court.

At the sentencing on Tuesday, Judge Martin Picton said if the drugs had reached the UK they could have resulted in “appalling social harm”.

The seized cocaine on board a Border Force cutter. Photograph: National Crime Agency/PA

SY Nomad was intercepted as part of a National Crime Agency-led operation on 29 August last year as it neared the end of its voyage from Suriname in South America. The cocaine was wrapped in kilo blocks found inside storage lockers on board the vessel. Its street value once cut and adulterated was estimated to be £112m.

Must, the skipper, and Gailis and Dijkstra, his two crew members, were on board the catamaran. Meanwhile, Clark had been observed with a rigid-hulled inflatable boat in Hayle, north Cornwall. Waters had purchased a GPS device, thermal cameras and other maritime equipment, including a repair kit for the inflatable boat and a solar-charged portable inflator.

Officers believed the plan was for the inflatable to meet the SY Nomad at sea and transfer the drugs over for onward distribution in the UK. It took more than a year for the smuggler to organise the run and the interception was one of the UK’s largest seizures of class A drugs.

The cocaine was found within the storage lockers of the SY Nomad. Photograph: National Crime Agency/PA

Ty Surgeon, the senior NCA investigating officer, said: “This was an audacious plan to bring cocaine to the UK by boat and it was only thwarted through law enforcement and partner agencies working together, sharing intelligence and conducting operational activity to stop it.

“The main instigators, Clark and Waters, both of whom have previous convictions for drug trafficking offences, are professional drug smugglers. They knew exactly what they were doing and had planned every part of the attempt.”

Clark and Waters were each sentenced to 28 years, Must for 30 years, Dijkstra was given an 18-year sentence, and Gailis was sentenced to 16 years.