Ten nations, about 20 ships and 5,300 personnel are taking part in Rim of the Pacific maritime exercises starting Monday in Hawaii’s waters.

This year, the prestigious interoperability exercise is a coronavirus-reduced shadow of its former self.

Two years ago, the last time the biennial exercise was held, 25 nations, 46 surface ships, five submarines, 17 land forces, more than 200 aircraft and 25,000 personnel were part of the drills. All the participants were reinvited for 2020.

South Korea, Canada, Australia, Japan, the Philippines, Singapore, New Zealand, Brunei and France are participating in 2020 alongside the United States.

RIMPAC was over a month long in 2018. Amid the pandemic it was trimmed to two weeks and pushed back from July.

Almost all of the activity this time will be at sea, with the exercise scheduled to end Aug. 31.

Some, but not all, visiting ships are already in Pearl Harbor for what the Navy said are logistics stops ahead of the exercise, with sailors not leaving the ship or pier.

Gone this time, due to COVID-19, is the harbor phase with final planning, parties and sporting events such as soccer between countries as well as free time — and spending — in Waikiki, according to the Royal Canadian Navy.

Navy Region Hawaii in years past said RIMPAC provided a more than $50 million boost to Hawaii’s economy.

A “free play” scenario usually held at the end of the sea phase also has been canceled. A U.S. aircraft carrier is not participating this time — although the 844-foot helicopter carrier USS Essex out of San Diego is here.

Japan sent the big helicopter destroyer Ise and destroyer Ashigara. South Korea sent two destroyers.

The Philippine Navy said the missile frigate BRP Jose Rizal and about 100 crew coming to Hawaii tested negative for COVID-19 as of July 23 — with the exception of two crew members who previously tested positive and were quarantined and receiving treatment.

The Jose Rizal arrived in Guam on Aug. 2 and is expected to be in Pearl Harbor Friday.

There will be no amphibious storm-the-beach operations this RIMPAC. The air component also was canceled.

“The at-sea-only construct for RIMPAC 2020 was developed to ensure the safety of all military forces participating by minimizing shore-based contingents. This modified plan will allow us to conduct a meaningful exercise with maximum training value and minimum risk to the force, allies and partners, and the people of Hawaii,” Cmdr. John Fage, a spokesman for the Navy’s 3rd Fleet in San Diego, said previously.

The 3rd Fleet plans the exercise while U.S. Pacific Fleet hosts it.