Note
Go to the end to download the full example code.
Ship drift
from datetime import datetime
from opendrift.models.shipdrift import ShipDrift
o = ShipDrift(loglevel=20)
o.add_readers_from_list([
'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml',
'https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc',
'https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml'
])
10:06:53 INFO opendrift:568: OpenDriftSimulation initialised (version 1.14.3 / v1.14.3-6-g4ace059)
Seed ship elements at defined position and time Note: beam/length ratio is larger than allowed, but is then clipped internally
o.seed_elements(lon=5.0, lat=63.0, radius=1000, number=1000,
time=datetime.now(),
length=80.0, beam=20.0, height=9.0, draft=4.0)
10:06:53 WARNING opendrift.models.shipdrift:181: Ratio of beam to length should be in range 0.12 to 0.18, given range is 0.25-0.25. Using border value.
10:06:53 INFO opendrift.models.basemodel.environment:206: Adding a global landmask from GSHHG
10:06:58 INFO opendrift.models.basemodel.environment:229: Fallback values will be used for the following variables which have no readers:
10:06:58 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_stokes_drift_x_velocity: 0.000000
10:06:58 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_stokes_drift_y_velocity: 0.000000
10:06:58 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_significant_height: 0.000000
10:06:58 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
Running model
o.run(steps=24, stop_on_error=True)
10:06:58 INFO opendrift:1789: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
10:06:58 INFO opendrift:1789: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
10:06:58 INFO opendrift:944: Using existing reader for land_binary_mask to move elements to ocean
10:06:58 INFO opendrift:974: All points are in ocean
10:06:58 INFO opendrift:2085: 2025-09-18 10:06:53.933031 - step 1 of 24 - 1000 active elements (0 deactivated)
10:06:58 INFO opendrift.readers:61: Opening file with xr.open_dataset
10:07:00 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}
10:07:00 INFO opendrift.readers:61: Opening file with xr.open_dataset
10:07:00 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
10:07:00 INFO opendrift.readers:61: Opening file with xr.open_dataset
10:07:03 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'y': 'rlat', 'x': 'rlon', 'time': 'time'}
10:07:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:06 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:06 INFO opendrift:2085: 2025-09-18 11:06:53.933031 - step 2 of 24 - 1000 active elements (0 deactivated)
10:07:07 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:07 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:08 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:08 INFO opendrift:2085: 2025-09-18 12:06:53.933031 - step 3 of 24 - 1000 active elements (0 deactivated)
10:07:09 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:09 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:09 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:09 INFO opendrift:2085: 2025-09-18 13:06:53.933031 - step 4 of 24 - 1000 active elements (0 deactivated)
10:07:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:11 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:11 INFO opendrift:2085: 2025-09-18 14:06:53.933031 - step 5 of 24 - 1000 active elements (0 deactivated)
10:07:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:13 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:13 INFO opendrift:2085: 2025-09-18 15:06:53.933031 - step 6 of 24 - 1000 active elements (0 deactivated)
10:07:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:14 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:14 INFO opendrift:2085: 2025-09-18 16:06:53.933031 - step 7 of 24 - 1000 active elements (0 deactivated)
10:07:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:16 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:16 INFO opendrift:2085: 2025-09-18 17:06:53.933031 - step 8 of 24 - 1000 active elements (0 deactivated)
10:07:17 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:17 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:18 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:18 INFO opendrift:2085: 2025-09-18 18:06:53.933031 - step 9 of 24 - 1000 active elements (0 deactivated)
10:07:19 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:19 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:19 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:19 INFO opendrift:2085: 2025-09-18 19:06:53.933031 - step 10 of 24 - 1000 active elements (0 deactivated)
10:07:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:21 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:21 INFO opendrift:2085: 2025-09-18 20:06:53.933031 - step 11 of 24 - 1000 active elements (0 deactivated)
10:07:22 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:22 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:23 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:23 INFO opendrift:2085: 2025-09-18 21:06:53.933031 - step 12 of 24 - 1000 active elements (0 deactivated)
10:07:24 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:24 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:25 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:25 INFO opendrift:2085: 2025-09-18 22:06:53.933031 - step 13 of 24 - 1000 active elements (0 deactivated)
10:07:26 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:26 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:26 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:26 INFO opendrift:2085: 2025-09-18 23:06:53.933031 - step 14 of 24 - 1000 active elements (0 deactivated)
10:07:28 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:28 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:29 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:29 INFO opendrift:2085: 2025-09-19 00:06:53.933031 - step 15 of 24 - 1000 active elements (0 deactivated)
10:07:30 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:30 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:31 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:31 INFO opendrift:2085: 2025-09-19 01:06:53.933031 - step 16 of 24 - 1000 active elements (0 deactivated)
10:07:32 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:32 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:33 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:33 INFO opendrift:2085: 2025-09-19 02:06:53.933031 - step 17 of 24 - 1000 active elements (0 deactivated)
10:07:34 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:34 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:35 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:35 INFO opendrift:2085: 2025-09-19 03:06:53.933031 - step 18 of 24 - 1000 active elements (0 deactivated)
10:07:36 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:36 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:37 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:37 INFO opendrift:2085: 2025-09-19 04:06:53.933031 - step 19 of 24 - 1000 active elements (0 deactivated)
10:07:38 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:38 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:39 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:39 INFO opendrift:2085: 2025-09-19 05:06:53.933031 - step 20 of 24 - 1000 active elements (0 deactivated)
10:07:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:41 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:41 INFO opendrift:2085: 2025-09-19 06:06:53.933031 - step 21 of 24 - 1000 active elements (0 deactivated)
10:07:42 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:42 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:43 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:43 INFO opendrift:2085: 2025-09-19 07:06:53.933031 - step 22 of 24 - 1000 active elements (0 deactivated)
10:07:44 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:44 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:45 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:45 INFO opendrift:2085: 2025-09-19 08:06:53.933031 - step 23 of 24 - 1000 active elements (0 deactivated)
10:07:46 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:46 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:47 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:07:47 INFO opendrift:2085: 2025-09-19 09:06:53.933031 - step 24 of 24 - 1000 active elements (0 deactivated)
10:07:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:07:49 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
Print and plot results
print(o)
o.plot(linecolor='orientation')
#o.animation(color='orientation', markersize=20, filename="orientation.gif", legend=['left','right'],colorbar=False,cmap='bwr')
o.animation(color='orientation', legend=['left','right'], markersize=20, colorbar=False, cmap='bwr')

===========================
--------------------
Reader performance:
--------------------
global_landmask
0:00:00.0 total
0:00:00.0 preparing
0:00:00.0 reading
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
0:00:15.2 total
0:00:00.0 preparing
0:00:15.1 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
0:00:13.9 total
0:00:00.0 preparing
0:00:13.9 reading
0:00:00.2 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
0:00:16.0 total
0:00:00.0 preparing
0:00:15.9 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
Performance:
55.7 total time
4.4 configuration
0.0 preparing main loop
0.0 moving elements to ocean
51.3 main loop
0.4 updating elements
0.0 cleaning up
--------------------
===========================
Model: ShipDrift (OpenDrift version 1.14.3)
1000 active ShipObject particles (0 deactivated, 0 scheduled)
-------------------
Environment variables:
-----
land_binary_mask
1) global_landmask
-----
x_sea_water_velocity
y_sea_water_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
2) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
x_wind
y_wind
1) https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
-----
sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
sea_surface_wave_significant_height
sea_surface_wave_stokes_drift_x_velocity
sea_surface_wave_stokes_drift_y_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
Discarded readers:
Time:
Start: 2025-09-18 10:06:53.933031 UTC
Present: 2025-09-19 10:06:53.933031 UTC
Calculation steps: 24 * 1:00:00 - total time: 1 day, 0:00:00
Output steps: 25 * 1:00:00
===========================
10:08:02 INFO opendrift:4612: Saving animation to /root/project/docs/source/gallery/animations/example_shipdrift_0.gif...
10:08:16 INFO opendrift:3053: Time to make animation: 0:00:14.978925

Total running time of the script: (1 minutes 30.938 seconds)