Countries that border the Pacific are taking part in a massive exercise called "Rim of the Pacific" or "RIMPAC." Dozens of ships, hundreds of aircraft, and thousands of people are practicing their warfighting skills in RIMPAC.
Military photographers and videographers have been sending out hundreds of excellent photos and videos from the exercise this year, and here are 19 of the best of what they'd captured:
1. Marines and U.S. allies attacked the beaches of Hawaii in a simulated amphibious assault
US Marines conduct an amphibious assault during Rim of the Pacific 2016. (Photo: US Navy Mass Communication Specialist 2nd Class Katarzyna Kobiljak)
2. Once the Marines hit the sand, they flooded out of their vehicles and got to work
US Marines land on the sands of Hawaii during a joint exercise beach assault with the Japan Self Defense Force. (GIF: US Marine Corps Cpl. Natalie Dillon)
3. Marine attack helicopters flew overhead and provided support to the guys on the ground
A Marine Corps AH-1W Super Cobra with Marine Light Attack Helicopter Squadron (HMLA) 367 protects US Marines during a beach assault as part of Rim of the Pacific 2016. (Photo: US Navy Mass Communication Specialist 2nd Class Katarzyna Kobiljak)
5. Ashore, infantry Marines prepped for the hard fight to the island's interior
US Marines move their mortars forward during a beach assault in Rim of the Pacific 2016. (Photo: US Marine Corps Lance Cpl. Matthew Casbarro)
6. At training areas past the sand, the Marines practiced assaulting buildings and bunkers
US Marines participate in an amphibious assault on Bellows Beach, Hawaii, during Rim of the Pacific 2016. (Photo: Royal New Zealand Navy Petty Officer Chris Weissenborn)
7. They even went to firing ranges to practice making stuff blow up
US Marines operate in Pohakuloa Training Area, Hawaii July 20, 2016. (GIF: US Marine Corps Cpl. Isaac Ibarra)
8. Out at sea, the Navy got in the action with a large formation of 40 ships that included some surprising participants ...
Forty ships and submarines sail in close formation during Rim of the Pacific 2016. (Photo: US Navy Mass Communication Specialist 1st Class Ace Rheaume)
BTW, if you want to see hundreds of photos of these 40 ships sailing next to each other, just click on this link. Literally hundreds. There are different angles and close-ups on dozens of the ships available.
9. ... like the Coast Guard's USCGC Stratton ...
USCGC Stratton steams through the Pacific (Photo: US Navy Mass Communication Specialist 1st Class Ace Rheaume)
10. ... and a Chinese hospital ship, the Peace Ark
The Chinese hospital ship Peace Ark got in on the action of Pacific Rim. (Photo: US Navy Mass Communication Specialist 1st Class Ace Rheaume)
11. Onboard the Peace Ark, doctors and other medical personnel practiced treating patients and responding to humanitarian crises
Chinese medical personnel aboard the hospital ship Peace Ark treat simulated injuries during Rim of the Pacific 2016. (Photo: Chinese Navy)
12. Another Chinese ship, the multirole frigate Hengshui, fired on targets to display its proficiency
The Chinese Navy frigate Hengshui fires its main gun at a towed target during Rim of the Pacific 2016. (Photo: Chinese Navy Senior Capt. Liu Wenping)
13. Under the waves, a New Zealand dive unit had to locate an 18-foot shipping container and assist in its recovery
Photo: New Zealand Defence Force Photographer Petty Officer Chris Weissenborn
14. A Canadian team found and interrogated an underwater wreck during their training
Canadian divers held their training at an underwater range on July 17, 2016, as part of Rim of the Pacific. (GIF: Canadian Forces Combat Camera Master Corporal Christopher Ward)
15. Forces from four allied countries land on a "captured" beach on a Royal Australian Navy landing craft
A Royal Australian Navy landing craft transports Australian, New Zealand, Tongan, and US forces to a Hawaii beach on Jul. 30. (Photo: US Marine Corps Sgt. William L. Holdaway)
16. Military vehicles laid down beach matting to prevent other vehicles from slipping on the loose sand. The matting can be laid down in combat to allow tanks and other heavy vehicles to assault towards their objectives quickly
An LX-120 front end loader lays down beach matting during Rim of the Pacific 2016. The matting makes it easier for follow-on vehicles to cross the loose sand. (Photo: US Marine Corps Sgt. William L. Holdaway)
17. Royal Australian combat engineers cleared the way inland for allied forces by searching out mines and other simulated explosives
Royal Australian Army Sgt. Connor Chamney syncs his mine calibration equipment Jul. 30. (Photo: US Marine Corps Sgt. William Holdaway)
18. Air Force F-22 Raptors and a tanker aircraft assisted with the exercise, allowing the Air Force to improve its interoperability with the U.S. Navy and foreign militaries
Three US Air Force F-22 Raptors refuel from a KC-135R Stratotanker during Rim of the Pacific 2016. (Photo: US Navy Mass Communication Specialist 2nd Class Gregory A. Harden II)
19. The Mexican Navy sent small craft to southern California to practice working with U.S. Navy riverine craft, the small boats that patrol rivers and other tight waterways
A Mexican Navy coastal patrol boat practices tactical maneuvers during a mission with the US Navy's Coastal Riverine Squadron 1 in Rim of the Pacific 2016. (Photo: US Navy Mass Communication Specialist 2nd Class Jonathan A. Nelson)
RIMPAC takes place on most even-numbered years and has been held 25 times since 1971. America's traditional allies in the Pacific usually attend, but some rivals like Russia and China are common guests as well.