Wave Whisperer™

Read the buoy. Watch the water. Train your call.

Buoy School

What a buoy is and how it works.

A swell is a train of waves from a distant storm. A buoy is the float that measures it: rise and fall give height and period, the push gives direction.

A Waverider at the surface, mooring running to the seabed.

How a buoy measures a wave.

The sphere below is a Datawell Waverider, the buoy Scripps Institution of Oceanography moors off California.

The hull rides the surfaceA stainless sphere about 3 ft (0.9 m) across, moored on a long elastic tether so it follows the water.
A weighted platform stays levelA heavy disc floats in fluid inside the hull. The hull tilts around it, so the sensor has a true vertical.
It measures acceleration, not heightFrom how hard it is lifted and dropped, it works out how far it rose and fell.
Horizontal sensors add directionTwo more sensors and a compass track which way the buoy is pushed.
It sends a reading every 30 minutesIridium satellite, to a gateway in Honolulu, to Scripps in La Jolla. That is the delay in the timestamp.

The hull follows the wave. The platform inside stays level, and that is what makes the reading accurate.

What is on top.

Top-down view of an open instrument hatch on a yellow buoy, with sealed stainless fittings and a bolted rim. — The hatch open on the bench. The antenna base talks to the satellite; the sealed port beside it carries the GPS receiver.

The upper hemisphere of a yellow buoy at sea, carrying a whip antenna on a mast, a domed GPS receiver and a ring of dark solar cells set into the deck. — The same three parts in the water. Everything above the waterline is power, position and radio; the measuring happens out of sight, inside the hull.

What the two numbers mean.

Every buoy in the app shows one or two ID numbers. They tell you who runs it and what kind of buoy it is.

02846221Santa Monica Bay

028: Scripps's number. A yellow sphere built to measure waves, usually a few miles off the beach.
46221: NOAA's number for the same buoy. Many spheres are on NOAA's list too.
– 46025: No Scripps number: a weather buoy on NOAA's list. Bigger, mostly further out, with wind and pressure as well as waves.

Scripps spheres compared with NOAA weather buoys
	Scripps (CDIP)	NOAA (NDBC)
Looks like	A yellow sphere, 3 ft across	A flat 10 ft disc with a mast
Sits	Usually a few miles off the beach	Mostly further offshore
Measures	Waves, precisely, plus sea temperature	Waves, wind, pressure, air and sea temperature
Numbered	028, three digits	46025, five digits
In the app	44 stations	65 stations, 18 of them Canada's

A yellow spherical wave buoy low in grey-green chop, a whip antenna on top and a mooring line leaving the hull. — **Scripps sphere**3 ft across, a few miles off the beach. Measures waves and sea temperature. Three digits: 028.

A wide flat yellow disc buoy riding low in grey-green swell, its deck enclosed by a cage of yellow steel bars with a solar panel and a wind sensor on top, alone in open water. — **NOAA weather buoy**A 10 ft disc in a steel cage that keeps sea lions off, mostly further out. Adds wind and pressure. Five digits: 46025.

The 3 ft yellow sphere small in a wide stretch of open grey-green water, with a scale bar marked 3 feet and 10 feet beneath it. — **Same scale**Both pictures are drawn to one scale, so the bar under each measures the same distance.

The 10 ft caged yellow disc buoy filling much more of its frame than the sphere beside it, with a scale bar marked 3 feet and 10 feet beneath it. — **Three feet against ten**The weather buoy is more than three times across.

The four numbers.

What the buoy reports, what it does not, and how to read it if you are new.

Height

2.6ft

Average of the highest third of waves, not the biggest. Every swell combined into one number, adding as energy, not height: two 3 ft swells read about 4 ft, not 6.

Period

15.4s

Seconds between crests, for the swell carrying the most energy. Under 11 is usually local wind. Over 16 is a distant storm. Average period, a switch in the app, counts every wave, not just the peak.

Direction

185°

The compass direction the waves come from, so 185 means from the south. The buoy cannot tell you whether your spot faces that direction.

Sea surface temp

73°F

Measured in the top few feet, not at depth. Good for what to wear, and for spotting upwelling, cold deep water pulled up by wind, when it drops several degrees in a day.

Latest reading from CDIP 028 / NDBC 46221, Santa Monica Bay.

Every wave buoy on NOAA's North Pacific list.

All 109 wave-reporting stations on that list are in Wave Whisperer. A new install starts on the five nearest you, or ten California and reference buoys if you skip location. Buoy Selector in Settings adds any other.

NOAA lists 379 active stations in the North Pacific: 138 buoys, 224 towers and gauges on piers and platforms, 14 DART tsunami buoys and 3 uncrewed craft. 29 buoys were not reporting waves at the survey.

Not on the list: Sofar Spotters, Mexican and Asian networks, and CDIP stations without an NDBC feed. Open a row for its numbers, then Locate for the map.

Readings are the latest posted. CDIP spheres post twice an hour, NOAA and Canadian hulls once.

109 stations shown

CDIP	NDBC	Station	Closest town	Reporting
028	46221	Santa Monica Bay, CALos Angeles	Los Angeles 23 nm WSW	active

029	46214	Point Reyes, CASan Francisco	San Francisco 51 nm WNW	active

036	46211	Grays Harbor, WAWestport	Westport 6 nm WSW	active

045	46224	Oceanside Offshore, CAOceanside	Oceanside 6 nm W	active

067	46219	San Nicolas Island, CASanta Barbara	Santa Barbara 72 nm S	active

071	46218	Harvest, CASanta Barbara	Santa Barbara 54 nm W	active

076	46215	Diablo Canyon, CAMorro Bay	Morro Bay 10 nm S	active

092	46222	San Pedro, CALos Angeles	Los Angeles 27 nm S	active

094	46213	Cape Mendocino, CAEureka	Eureka 41 nm SW	active

098	51202	Mokapu Point, HIKailua	Kailua 3 nm ENE	active

100	46225	Torrey Pines Outer, CALa Jolla	La Jolla 9 nm NW	active

103	46268	Topanga Nearshore, CALos Angeles	Los Angeles 17 nm W	active

106	51201	Waimea Bay, HIHaleiwa	Haleiwa 5 nm N	active

139	46229	UMPQUA OFFSHORE, ORCoos Bay	Coos Bay 28 nm NNW	active

142	46237	San Francisco Bar, CASan Francisco	San Francisco 10 nm W	19d ago

153	46266	Del Mar Nearshore, CADel Mar	Del Mar 1 nm WSW	active

156	46236	Monterey Canyon Outer, CAMonterey	Monterey 10 nm NNW	active

157	46239	Point Sur, CAMonterey	Monterey 19 nm SW	active

162	46243	Clatsop Spit, ORAstoria	Astoria 13 nm W	active

166	46246	Ocean Station PAPASan Francisco	San Francisco 1227 nm NW	2h ago

168	46244	Humboldt Bay, North Spit, CAEureka	Eureka 11 nm WNW	active

179	46248	Astoria Canyon, ORAstoria	Astoria 34 nm W	active

187	51205	Pauwela, Maui, HIPaia	Paia 7 nm NNW	active

188	51206	Hilo, Hawaii, HIHilo	Hilo 8 nm NE	active

191	46232	Point Loma South, CASan Diego	San Diego 21 nm SW	active

201	46254	SCRIPPS Nearshore, CASan Diego	San Diego 8 nm NW	active

202	51208	Hanalei, Kauai, HIHanalei	Hanalei 6 nm NW	active

203	46251	Santa Cruz Basin, CASanta Barbara	Santa Barbara 40 nm S	active

204	46108	Lower Cook InletHomer	Homer 9 nm WSW	active

213	46253	San Pedro South, CALong Beach	Long Beach 12 nm S	active

215	46256	Long Beach Channel, CALong Beach	Long Beach 5 nm S	active

220	46258	Mission Bay West, CASan Diego	San Diego 18 nm W	active

222	46259	Santa Lucia Escarpment, CAPismo Beach	Pismo Beach 47 nm WSW	active

225	51210	Kaneohe Bay, WETS, HIKaneohe	Kaneohe 4 nm NE	39d ago

233	51211	Pearl Harbor Entrance, HIHonolulu	Honolulu 6 nm W	active

238	51212	Barbers Point, Kalaeloa, HIEwa Beach	Ewa Beach 8 nm W	active

239	51213	Kaumalapau Southwest, Lanai, HILanai City	Lanai City 7 nm SW	40d ago

248	46267	Angeles Point, WAPort Angeles	Port Angeles 7 nm WNW	active

262	46274	Leucadia Nearshore, CAEncinitas	Encinitas 2 nm NW	active

264	46275	Red Beach Nearshore, CAOceanside	Oceanside 10 nm NW	active

270	46278	Tillamook Bay South Jetty, ORTillamook	Tillamook 9 nm NW	active

271	46277	Green Beach Offshore, CAOceanside	Oceanside 18 nm WNW	active

280	46283	Yaquina Channel SW, ORNewport	Newport 9 nm WSW	43d ago

284	46285	Capistrano Beach Nearshore, CADana Point	Dana Point 2 nm SE	active

–	46001	WESTERN GULF OF ALASKA - 175NM SE of Kodiak, AKKodiak	Kodiak 169 nm ESE	active

–	46002	WEST OREGON - 275NM West of Coos Bay, ORCoos Bay	Coos Bay 281 nm W	active

–	46004	Middle NomadSandspit	Sandspit 210 nm SW	active

–	46005	WEST WASHINGTON - 300NM West of Aberdeen, WATofino	Tofino 275 nm SW	active

–	46011	SANTA MARIA - 21NM NW of Point Arguello, CAPismo Beach	Pismo Beach 21 nm SW	active

–	46012	HALF MOON BAY - 24NM SSW of San Francisco, CAHalf Moon Bay	Half Moon Bay 23 nm WSW	active

–	46013	BODEGA BAY - 48NM NW of San Francisco, CABodega Bay	Bodega Bay 14 nm WSW	active

–	46014	PT ARENA - 19NM North of Point Arena, CAMendocino	Mendocino 10 nm WSW	active

–	46015	PORT ORFORD - 15 NM West of Port Orford, ORCoos Bay	Coos Bay 46 nm SW	active

–	46022	EEL RIVER - 17NM WSW of Eureka, CAEureka	Eureka 18 nm WSW	active

–	46025	Santa Monica Basin - 33NM WSW of Santa Monica, CASanta Monica	Santa Monica 33 nm WSW	active

–	46026	SAN FRANCISCO - 18NM West of San Francisco, CASan Francisco	San Francisco 20 nm W	active

–	46027	ST GEORGES - 8 NM NW of Crescent City, CACrescent City	Crescent City 10 nm WNW	active

–	46028	CAPE SAN MARTIN - 55NM West NW of Morro Bay, CAMonterey	Monterey 50 nm S	active

–	46029	COLUMBIA RIVER BAR - 20NM West of Columbia River MouthAstoria	Astoria 28 nm W	active

–	46035	CENTRAL BERING SEA - 310 NM North of Adak, AKAtka	Atka 312 nm NNW	active

–	46036	South NomadPort Hardy	Port Hardy 288 nm WSW	active

–	46041	CAPE ELIZABETH - 45NM NW of Aberdeen, WAAberdeen	Aberdeen 44 nm WNW	active

–	46042	MONTEREY - 27NM WNW of Monterey, CASanta Cruz	Santa Cruz 21 nm WSW	active

–	46047	TANNER BANK - 121 NM West of San Diego, CALong Beach	Long Beach 106 nm SW	active

–	46050	STONEWALL BANK - 20NM West of Newport, ORNewport	Newport 21 nm W	active

–	46053	EAST SANTA BARBARA - 12NM Southwest of Santa Barbara, CASanta Barbara	Santa Barbara 13 nm SW	active

–	46054	WEST SANTA BARBARA 38 NM West of Santa Barbara, CASanta Barbara	Santa Barbara 39 nm WSW	active

–	46059	WEST CALIFORNIA - 357NM West of San Francisco, CAMendocino	Mendocino 295 nm WSW	active

–	46060	WEST ORCA BAY - 8NM NW of Hinchinbrook Is., AKCordova	Cordova 31 nm W	active

–	46061	Seal Rocks - Between Montague and Hinchinbrook Islands, AKCordova	Cordova 37 nm WSW	active

–	46066	SOUTH KODIAK - 310NM SSW of Kodiak, AKPerryville	Perryville 238 nm SE	active

–	46069	SOUTH SANTA ROSA - 14 NM SW of Santa Rosa Island, CASanta Barbara	Santa Barbara 53 nm SSW	active

–	46072	CENTRAL ALEUTIANS 230 NM SW Dutch HarborAtka	Atka 83 nm ESE	active

–	46073	SOUTHEAST BERING SEA - 205 NM WNW of Dutch Harbor, AKNikolski	Nikolski 162 nm NW	active

–	46075	SHUMAGIN ISLANDS - 85NM South of Sand Point, AKSand Point	Sand Point 85 nm S	active

–	46076	CAPE CLEARE - 17 NM South of Montague Is, AKSeward	Seward 56 nm SE	active

–	46077	SHELIKOF STRAIT, AKKarluk	Karluk 19 nm NNE	active

–	46078	ALBATROSS BANK - 104NM South of Kodiak Is., AKKodiak	Kodiak 134 nm S	active

–	46080	PORTLOCK BANK - 76 NM ENE of Kodiak, AKKodiak	Kodiak 73 nm E	active

–	46081	Western Prince William SoundWhittier	Whittier 12 nm E	active

–	46082	Cape Suckling - 35 NM SE of Kayak Is, AKCordova	Cordova 89 nm SE	active

–	46083	FAIRWEATHER GROUND - 105 NM West of Juneau, AKHoonah	Hoonah 82 nm W	active

–	46084	CAPE EDGECUMBE - 25NM SSW of Cape Edgecumbe, AKSitka	Sitka 36 nm SW	active

–	46085	CENTRAL GULF OF ALASKA - 265NM West of Cape Ommaney, AKYakutat	Yakutat 245 nm SSW	active

–	46086	SAN CLEMENTE BASIN - 27NM SE Of San Clemente Is, CASan Diego	San Diego 46 nm WSW	active

–	46087	Neah Bay - 6 NM North of Cape Flattery, WA (Traffic Separation Lighted Buoy)Nanaimo	Nanaimo 50 nm SW	active

–	46088	NEW DUNGENESS - 17 NM NE of Port Angeles, WAPort Angeles	Port Angeles 16 nm NE	active

–	46089	TILLAMOOK, OR - 85 NM WNW of Tillamook, ORAstoria	Astoria 84 nm W	active

–	46131	Sentry ShoalCampbell River	Campbell River 12 nm ESE	active

–	46132	South BrooksPort Hardy	Port Hardy 58 nm SSW	active

–	46145	Central Dixon Entrance BuoyHydaburg	Hydaburg 52 nm SSE	active

–	46146	Halibut BankNanaimo	Nanaimo 14 nm NE	active

–	46147	South MoresbySandspit	Sandspit 88 nm SSE	active

–	46181	Nanakwa ShoalKitimat	Kitimat 15 nm SSW	active

–	46183	North Hecate StraitSandspit	Sandspit 35 nm NE	active

–	46184	North NomadSitka	Sitka 223 nm SSW	active

–	46185	South Hecate StraitBella Bella	Bella Bella 64 nm WNW	active

–	46204	West Sea OtterBella Bella	Bella Bella 52 nm SSW	active

–	46205	West Dixon EntranceHydaburg	Hydaburg 81 nm SW	active

–	46206	La Perouse BankTofino	Tofino 16 nm SSW	active

–	46207	East DellwoodPort Hardy	Port Hardy 92 nm W	active

–	46208	West MoresbySandspit	Sandspit 53 nm SW	active

–	46303	Southern Georgia StraitVancouver	Vancouver 19 nm SW	active

–	46304	Entrance To English BayVancouver	Vancouver 9 nm W	active

–	46453	Backyard Buoys - Quinault NorthAberdeen	Aberdeen 38 nm NW	active

–	51000	NORTHERN HAWAII ONE - 245NM NE of Honolulu HIWailuku	Wailuku 220 nm NE	active

–	51001	NORTHWESTERN HAWAII ONE - 188 NM NW of Kauai Island, HILihue	Lihue 210 nm NW	active

–	51002	SOUTHWEST HAWAII - 215NM SSW of Hilo, HIKailua-Kona	Kailua-Kona 184 nm SSW	active

–	51004	SOUTHEAST HAWAII - 205 NM Southeast of Hilo, HIHilo	Hilo 211 nm SE	active

All 109 in the app. Free 30-day trial, then $1.99 once.

App Store → Google Play →

Where to read more.

Start with the first three. The rest go deeper. Each one shows its method and its data.

Start here

Stormsurf: Surf Forecast Tutorials

Mark Sponsler's full forecasting method, free. The closest thing to a course in reading buoys.

Start here

WaveCast: Nathan Todd Cool

Wrote an early book on surf forecasting, and teaches it from free public buoy data rather than a paid feed.

Start here

Surfertoday: the yellow wave buoys

Written for surfers rather than engineers. The best answer to "what is that yellow thing out there".

Deeper

Surfline: how LOLA reads the buoys

Surfline on why one significant wave height, the buoy's height number, is often two or three separate swells.

Deeper

CDIP: Instrumentation

Scripps documenting its own hardware. How a Waverider senses a wave, in plain language.

Deeper

CDIP: Data Acquisition

The path a reading takes: hull, to Iridium satellite, to Honolulu, to La Jolla, to your phone.

Deeper

NDBC: Can You Describe the Moored Buoys?

NOAA's hull types with dimensions. The 3-meter discus is what most of the offshore numbers come from.

Deeper

Datawell: Directional Waverider 4

The manufacturer. Specs and manuals for the sphere itself, including the sensor cutaways.

Deeper

Sofar Ocean: Spotter

A newer design: 2,500-plus small solar buoys, moored and drifting, feeding forecast models directly.

Deeper

Houghton et al. 2022, Geophysical Research Letters

Peer-reviewed, on assimilating buoy spectra into wave forecasts. For when you want the actual paper.