Send a coordinate and a moment, past or future. One REST call returns the tide height at that exact point, the next high and the next low, in milliseconds.
A real request, every loop: each spot is a live call to our own API on a ~3.7 km ocean grid - the curve, the highs and lows, and the response time are exactly what it returned.
SEE IT WORK
Pick a point and a time. Get the real tide back.
The live API, no key needed. Click the map to pick a point. On land we snap to the nearest coast and show you where; far inland there is no ocean tide and the API says so. Change the moment or the datum and the request and response below update to exactly what your code would send and receive.
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WHY TEAMS BUILD ON IT
The most precise tides on the planet, wherever your users tap.
Any coordinate, any date in history or the future, one REST call. Validated against independent tide gauges to about a centimetre and a half at the coast, and every response names the grid point it used.
~1.5 cm
typical at the coast
Any point
on Earth - not a station list
Any moment
past or future, on demand
~3 ms
typical warm response
Height at the exact point
The tide height at the coordinate you send, resolved on a ~3.7 km ocean grid rather than at a station up the coast. A creek, a flat, a mooring: the number is for that spot.
Turning times, not just heights
The next high and low, and every high and low in any window you ask for, with heights signed against the datum you chose. Enough to time a crossing, a launch or a dry-out.
Any moment, past or future
Astronomical tide is computed from harmonic constants at request time. A date next year or in 1998 costs the same milliseconds as now.
Beside the rest of the sea
The same key serves waves, wind, currents and sea temperature from Mareel Waters, so a tide series can sit next to the forecast in one screen.
BUILT ON
Open data from the institutions that measure the planet.
Mareel serves public Earth-observation data as an API. Every response carries the attribution of the source that produced it.
Tides
FES2022 global ocean tide model (AVISO / CNES / LEGOS / NOVELTIS / CLS)
Waters
NOAA GFS-Wave (WAVEWATCH III)
Copernicus Marine wave models - MFWAM global + IBI, Mediterranean, Baltic & Black Sea regional
MET Norway - MET Nordic 1 km analysis/forecast + MEPS 2.5 km (MetCoOp)
Reference every tide to the level you actually need.
Heights come back from mean sea level by default. Pick a datum in the live demo above - or name one in any call - and the whole series re-references: to the chart datum a navigator reads, the spring high a harbour plans around, the lowest water a hull has to clear. We compute the full family at any point from an 18.6-year tidal reduction, and label every value computed or official.
LAT
Chart datum
The zero a nautical chart is drawn to. Ask for datum=LAT and every height reads as a depth a navigator trusts. Computed worldwide; official where a hydrographic office publishes one.
HAT
Highest astronomical tide
The highest level astronomy alone produces - bridge and cable clearance, the top of the intertidal. Its counterpart LAT is the chart datum above.
MHWS · MLWS · MHWN · MLWN
Springs & neaps
Mean high and low water at spring and neap tides - the levels a harbour and intertidal work are planned around.
MHW / MLW
Mean high & low water
The everyday high- and low-water average at the exact spot.
MHHW / MLLW
Diurnal extremes
The higher high and lower low of each tidal day. MLLW is the chart datum used across the Americas.
MTL · DTL
Tide levels
The mid-levels between the highs and lows - a steady reference to hang everything else on.
# default - heights from mean sea level
GET /v1/tides/heights?lat=48.36&lon=-4.55
# re-reference the whole series to chart datum
GET /v1/tides/heights?lat=48.36&lon=-4.55&datum=LAT
# the full family at a point, each value flagged
# computed (FES2022) or official
GET /v1/tides/datums?lat=48.36&lon=-4.55