Every year, for a short window after dark, coral reefs release new life into the water. The event is quiet, fragile, and easy to miss. For most people, coral spawning is something they only encounter through documentaries or scientific summaries after the fact. In Shenzhen's Dapeng waters, a volunteer dive team set out to change that by bringing the event to public screens as it happened, with the divers themselves doing the talking.
On the night of May 12, 2026, DiveForLove (深圳市大鹏新区珊瑚保育志愿联合会), the Shenzhen Dapeng New District Coral Conservation Volunteer Federation, ran its 2026 "Life to Life" (生与生 / Make it Live) coral spawning livestream from Da'ao Bay. The DIVEVOLK SeaLink Underwater Smartphone Data Transmitter carried the live signal. The whole rig went aboard one boat, carried by the volunteer dive team itself: a smartphone sealed in a DIVEVOLK underwater housing, a SeaLink unit running up to a floating surface unit, and night-dive lighting. No broadcast truck, cabling, or camera crew was involved.
What separates this year's broadcast from the 2025 attempt is sound. Divers worked in full face masks, and their voices travelled over Bluetooth into the phone inside its housing, then up through SeaLink alongside the live image. During the minutes when the colonies released their gametes, the commentary came from the diver on site. No presenter on shore had to narrate the returning feed second-hand.
Coral Spawning Is a Once-a-Year Event That Lasts Minutes
Coral spawning is the sexual reproduction of reef-building corals, and it is how a coral population maintains its genetic diversity and its capacity to adapt. Colonies release eggs and sperm into the water column, often within a synchronised window tied to the lunar cycle and to water temperature. Fertilised eggs develop into free-swimming planula larvae that drift on currents until they settle and found a new colony.
Three properties make the event difficult to reach. It happens at night. It lasts a short time, sometimes only minutes. And its exact date shifts from year to year, which is why documenting it takes repeated dives across weeks rather than a single scheduled shoot.
The stakes behind those dives are ecological. Reefs cover roughly 0.1 percent of the ocean floor yet provide habitat for about a quarter of all marine species, as NOAA's coral reef overview explains. Shenzhen sits on the northern edge of the Indo-Pacific coral distribution zone, and more than 60 stony coral species have been recorded in its waters, all listed as national second-class protected animals in China. When a coral colony spawns in Da'ao Bay, it is direct evidence that local water conditions still support reproduction rather than only survival.
What Changed Between Last Year and This Year
The 2025 livestream solved the picture. SeaLink carried live underwater video to the surface, and the public could watch coral spawning in Dapeng waters as it happened. Sound was another matter. A standard regulator fills a diver's mouth, and a sealed housing shuts the phone's microphone away from the water, so nobody could speak from the site. That year the commentary came from a presenter on shore reading the returning feed, or was dubbed in once the dive was over.
In 2026 the team closed that gap. Divers switched to full face masks. Their voice was picked up inside the mask, passed over Bluetooth into the phone in its housing, and travelled up with the live image. During the minutes when the colonies released, the audience heard what the diver was looking at, which colonies were going in synchrony, and which way the egg bundles were rising, at the moment they saw it.
The link runs both ways. Divers talk to each other to coordinate framing and lighting. Questions from the surface reach the water, and a diver can answer while the release is still under way. Talking with viewers in real time is what Dive Dive Live's underwater streams are built around, too.
That matters more for a local reef than for a distant one. Dapeng's corals grow beside one of China's largest cities, and most Shenzhen residents will never dive the site. Watching volunteers hold position in the dark while hearing why these colonies can still spawn this year is what makes the repeated dives concrete.
Cost decides who gets to run this at all. A volunteer organization has no outside broadcast unit. Once the chain fits into a phone, a housing, a voice module and a surface unit, conservation groups, marine educators and research teams can afford real-time underwater commentary too.
SeaLink Moves the Underwater Signal to the Surface
Water blocks the wireless signals a phone relies on, so a smartphone that streams reliably on land goes dark the moment it is submerged. SeaLink is built for that gap. It links the phone inside the underwater housing to a floating surface unit, supporting underwater signal transmission at depths of up to 30 meters and feeding live video, livestream audio and two-way communication into the same platforms a team already broadcasts on. That same link has already carried a live underwater TV broadcast to a news studio in Buenos Aires.
Night operations add their own demands. The team stages the phone, the housing seal and the pairing on the boat before entering the water, because nothing can be reconfigured once the housing is closed. The SeaTouch housings that carry the phone give divers full touchscreen control of the phone's native camera app underwater, so exposure and framing can be adjusted in the dark by hand, at the moment the corals begin to release.
How the Underwater Communication System Works
Getting a diver to narrate from underwater means solving three things in order: whether they can speak at all, whether that speech can reach the phone, and whether it can get from the phone to the surface.
The full face mask handles the first. A standard regulator occupies the mouth and leaves a diver unable to form clear words. A mask of the Ocean Reef type keeps the whole face in a dry space, so a diver breathes and speaks normally while a voice unit inside the mask picks up the audio. Swap in a two-way voice unit and divers can also talk to each other.
The DIVEVOLK Wireless Microphone Transmitter (WMT) handles the second. An audio cable runs from the mask's voice port into one end of the module; the other end pairs over Bluetooth with the phone inside the housing. The module weighs about 250 g and seats into a slot on the SeaLink body, so it stays put as the diver moves. Voice and image end up on the same phone, which means no audio to sync afterwards. Our WMT setup guide walks through the pairing step by step.
SeaLink handles the third. Bluetooth only covers the short hop into the housing. Carrying the phone's real-time signal up through the water is the job of the SeaLink Underwater Smartphone Data Transmitter.
With the three connected, the diver's voice and the underwater picture reach the surface broadcast end together. DIVEVOLK sells the combination as the SeaLink Neptune communication and livestream kit, so a team does not have to assemble it from separate systems.
Six Years of Spawning Records in Dapeng Waters
The 2026 broadcast follows a documentation record that DiveForLove has built since 2020.
- 2020: After four nights on station, volunteers filmed staghorn corals releasing pink egg bundles under a full moon, described by the team as "snowfall on the seabed." DiveForLove reports this as the first video record of coral spawning in Shenzhen's natural marine environment, and the first time a grassroots coral conservation organization in China documented coral sexual reproduction.
- 2021: Corals from a nursery planted six years earlier spawned on their own for the first time, a marker that restoration stock had reached reproductive maturity.
- 2023: A 14-night watch captured staghorn corals spawning on the nursery structures themselves.
- 2024: A fourth spawning record, in a year when sustained high water temperatures in Shenzhen put pressure on the coral nurseries and caused coral bleaching across regional waters.
- 2025: Volunteers documented a mass spawning across Dapeng waters, with tens of thousands of polyps releasing pink and orange gametes in synchrony. The same season, DiveForLove used DIVEVOLK SeaLink for its first smartphone livestream attempt around coral spawning, after a 40-day watch, drawing more than 100,000 viewers. The spawning coverage was picked up by China Central Television and other national media.
Connecting Field Science with Public Ocean Stewardship
The 2026 "Life to Life" livestream sits alongside DiveForLove's wider 2026 World Ocean Day activities, including an appearance at APEC · Nature Shenzhen, youth ocean conservation project sharing in Xiamen, and a June 8 science communication livestream from its coral conservation station in Dapeng. The organization has carried out coral restoration and habitat maintenance in Dapeng Bay and Da'ao Bay since 2013. Its core public message, "plant corals, plant hearts," reflects its position that reef recovery depends on ecological action and on long-term change in how the public behaves toward the sea. It is the same spirit as turning World Oceans Day into year-round action, rather than a single date on the calendar.
Coral cover in the waters around Shenzhen has been reported by DiveForLove as once reaching 70 percent before declining to roughly 30 percent under pressure from human activity and changing marine conditions. Reversing that trend takes nursery work and reef cleanups, and it also takes people who have seen the reef for themselves. When residents watch a live coral spawning broadcast on their phones and hear a diver explain it as it happens, the reef in their own city's waters becomes a place rather than a talking point. Divers who want to help can start smaller, logging reef observations as citizen scientists on their own dives.
Last year the picture came ashore. This year the voice came with it. DIVEVOLK's part is the link that lets the public stand next to the volunteers while corals release new life, and the same chain has since carried the Southern Media Group coral expedition livestream in the Greater Bay Area.
For teams planning educational broadcasts, ecological surveys, or scientific fieldwork, the DIVEVOLK x Ocean Reef audio dive kits cover the voice side, dive lights cover the dark, and our technical support center or contact page can help you work out whether a SeaLink-based workflow fits your project.
Field images from the 2026 broadcast courtesy of DiveForLove / DIVEVOLK. Coral spawning in Da'ao Bay on May 12, 2026 was photographed by Xiao Wei, DiveForLove operations manager, and by DiveForLove volunteers Huang Pei and Liu Yingzhi.
