Guess Your Time Swim

Leaving the GPS watch behind on the sand strips open-water swimming down to pure intuition, turning a morning race into an exercise in self-knowledge. The Guess Your Time Swim is an open-water sea race held in the Pacific Ocean at Kaimana Beach Park in Waikīkī, Honolulu, Hawaii. In this unique ocean challenge, participants submit their predicted finish time before diving in, and the swimmer whose actual clocking comes closest to their prediction takes the victory. On race morning, timing devices and watches are strictly prohibited on swimmers' wrists, forcing everyone to rely entirely on pace awareness and bodily rhythm. Swimmers can test their internal clock across two course options, choosing either a 1-mile (1,609 m) or a 2-mile (3,219 m) distance.

Both courses start and finish right at Kaimana Beach. Staged in October, the event features exceptionally comfortable ocean temperatures that typically hover between 76 and 80 degrees Fahrenheit. Without digital pacing alerts or lap splits to monitor, every stroke demands tuning in to the cadence of your breathing and the natural surge of the sea. The event is organized by the Waikiki Swim Club, while the renowned 2.35-mile Waikiki RoughWater Swim also takes place from Kaimana Beach every September. Beyond the friendly competition, the swim supports the Palekana Aquatics Academy, a local non-profit organization dedicated to providing essential water safety instruction and swim skills to children.

Diamond Head and Lēʻahi: the volcanic tuff cone above the bay

The dramatic profile of Diamond Head rises majestically just two kilometres away over Kaimana Beach. This vast volcanic tuff cone formed during explosive eruptions estimated to have occurred between 400,000 and 500,000 years ago. To native Hawaiians, the promontory is known as Lēʻahi, combining the words *lae* (promontory) and *ʻahi* (tuna), because the sharp ridgeline mirrors the dorsal fin of a tuna cutting across the surface. The peak later took on a crucial role in maritime and military defense, serving as a strategic lookout point providing panoramic views across the entire south shore of Oʻahu. In 1908, a trail was constructed to the summit for coastal defense operations, followed in 1917 by a navigational lighthouse built near the base of the crater slopes to steer incoming ships clear of the reefs.

Waikīkī reef: living corals and visiting monk seals

The protected swimming environment at Kaimana owes its calm conditions to a broad barrier reef that breaks the heavy ocean swell, leaving gentle inshore waters that are beloved for swimming, paddleboarding, and snorkeling. In 1978, the aquarium pioneered the display and cultivation of living Pacific corals in the United States using natural sunlight and seawater wells. It was also the first institution in the country to maintain the chambered nautilus and the first in the world to produce viable nautilus embryos, as well as caring for a giant clam from Palau that reached 38 years of age, setting a global record for aquarium longevity. Endangered Hawaiian monk seals occasionally haul out onto the soft sand at Kaimana Beach to rest or give birth. Encountering one of these wild marine mammals along the tide line is an unforgettable sight for visiting swimmers, though visitors are required to keep a respectful and safe distance so the resting animals remain protected and undisturbed.

Waikīkī shore: ancient canoe landings and royal waters

In early 1795, King Kamehameha I assembled a massive fleet of 1,200 war canoes to stage an amphibious landing on the southeastern shores of Oʻahu near Waikīkī and Waiʻalae, leading directly to the decisive Battle of Nuʻuanu five kilometres inland, where over 700 defending warriors fell from the sheer Nuʻuanu Pali cliff. Just years prior, in 1792, Captain William Brown anchored the sloops *Prince Lee Boo* and *Jackall* off Waikīkī, where island forces were later defeated by their crews in harbor skirmishes. At Kūhiō Beach Park, which was once the private estate of Pualeilani, ancient basaltic healer stones are known as the Stones of Life. In July 1918, Prince Kūhiō dismantled the tall board fence guarding his estate, opening a stretch of semi-protected beach and calm ocean water to the public.

Soon after, adjacent to the grand lānais of the historic Moana Hotel—whose name draws from the Hawaiian term for open sea—the visiting Prince of Wales was famously seen diving straight into the waves from a private hotel pier in 1920.

Kaimana Beach: hau tree shade and evening shoreline

Tucked away at the eastern end of Waikīkī, nestled between the Kaimana Beach Hotel and the historic Waikīkī Natatorium War Memorial, Kaimana Beach offers a distinctly intimate sanctuary away from the bustling high-rise center. When Scottish author Robert Louis Stevenson stayed at the original Sans Souci hotel here in 1893, he praised the quiet atmosphere, clear water, and dramatic shoreline scenery. That unhurried coastal rhythm continues after the morning race. Swimmers gather for breakfast and lunch directly on the waterfront at the Hau Tree restaurant, enjoying fresh island dishes shaded beneath the leafy canopy of historic hau trees. Alongside the sand, a broad grass lawn lined with coconut palms invites families and racers to spread towels for picnics and post-swim gatherings. As evening falls, both locals and visitors settle onto the sand to watch the sunset paint the sky in shifting colors over the calm reef channel where they gauged their strokes against the sea.