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'
])
12:21:30 INFO opendrift:568: OpenDriftSimulation initialised (version 1.14.9 / v1.14.9-47-gbdbbf88)
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)
12:21:30 WARNING opendrift.models.shipdrift:180: Ratio of beam to length should be in range 0.12 to 0.18, given range is 0.25-0.25. Using border value.
12:21:30 INFO opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
12:21:35 INFO opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
12:21:35 INFO opendrift.models.basemodel.environment:230: horizontal_diffusivity: 100.000000
12:21:35 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_x_velocity: 0.000000
12:21:35 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_y_velocity: 0.000000
12:21:35 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_significant_height: 0.000000
12:21:35 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
Running model
o.run(steps=24, stop_on_error=True)
12:21:35 INFO opendrift:1905: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
12:21:35 INFO opendrift:1905: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
12:21:35 INFO opendrift:947: Using existing reader for land_binary_mask to move elements to ocean
12:21:35 INFO opendrift:978: All points are in ocean
12:21:35 INFO opendrift:2202: 2026-05-11 12:21:30.676520 - step 1 of 24 - 1000 active elements (0 deactivated)
12:21:35 INFO opendrift.readers:67: Opening file with xr.open_dataset
12:21:36 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}
12:21:36 INFO opendrift.readers:67: Opening file with xr.open_dataset
12:21:37 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
12:21:37 INFO opendrift.readers:67: Opening file with xr.open_dataset
12:21:39 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'y': 'rlat', 'x': 'rlon', 'time': 'time'}
12:21:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:41 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:41 INFO opendrift:2202: 2026-05-11 13:21:30.676520 - step 2 of 24 - 1000 active elements (0 deactivated)
12:21:42 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:42 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:43 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:43 INFO opendrift:2202: 2026-05-11 14:21:30.676520 - step 3 of 24 - 1000 active elements (0 deactivated)
12:21:44 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:44 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:45 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:45 INFO opendrift:2202: 2026-05-11 15:21:30.676520 - step 4 of 24 - 1000 active elements (0 deactivated)
12:21:46 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:46 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:47 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:47 INFO opendrift:2202: 2026-05-11 16:21:30.676520 - step 5 of 24 - 1000 active elements (0 deactivated)
12:21:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:48 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:48 INFO opendrift:2202: 2026-05-11 17:21:30.676520 - step 6 of 24 - 1000 active elements (0 deactivated)
12:21:49 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:49 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:50 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:50 INFO opendrift:2202: 2026-05-11 18:21:30.676520 - step 7 of 24 - 1000 active elements (0 deactivated)
12:21:51 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:51 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:52 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:52 INFO opendrift:2202: 2026-05-11 19:21:30.676520 - step 8 of 24 - 1000 active elements (0 deactivated)
12:21:53 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:53 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:53 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:53 INFO opendrift:2202: 2026-05-11 20:21:30.676520 - step 9 of 24 - 1000 active elements (0 deactivated)
12:21:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:55 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:55 INFO opendrift:2202: 2026-05-11 21:21:30.676520 - step 10 of 24 - 1000 active elements (0 deactivated)
12:21:56 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:56 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:57 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:57 INFO opendrift:2202: 2026-05-11 22:21:30.676520 - step 11 of 24 - 1000 active elements (0 deactivated)
12:21:58 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:58 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:21:59 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:21:59 INFO opendrift:2202: 2026-05-11 23:21:30.676520 - step 12 of 24 - 1000 active elements (0 deactivated)
12:22:00 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:00 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:00 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:00 INFO opendrift:2202: 2026-05-12 00:21:30.676520 - step 13 of 24 - 1000 active elements (0 deactivated)
12:22:02 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:02 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:02 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:02 INFO opendrift:2202: 2026-05-12 01:21:30.676520 - step 14 of 24 - 1000 active elements (0 deactivated)
12:22:03 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:03 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:04 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:04 INFO opendrift:2202: 2026-05-12 02:21:30.676520 - step 15 of 24 - 1000 active elements (0 deactivated)
12:22:05 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:05 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:06 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:06 INFO opendrift:2202: 2026-05-12 03:21:30.676520 - step 16 of 24 - 1000 active elements (0 deactivated)
12:22:07 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:07 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:08 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:08 INFO opendrift:2202: 2026-05-12 04:21:30.676520 - step 17 of 24 - 1000 active elements (0 deactivated)
12:22:09 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:09 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:10 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:10 INFO opendrift:2202: 2026-05-12 05:21:30.676520 - step 18 of 24 - 1000 active elements (0 deactivated)
12:22:11 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:11 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:11 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:11 INFO opendrift:2202: 2026-05-12 06:21:30.676520 - step 19 of 24 - 1000 active elements (0 deactivated)
12:22:13 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:13 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:13 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:13 INFO opendrift:2202: 2026-05-12 07:21:30.676520 - step 20 of 24 - 1000 active elements (0 deactivated)
12:22:15 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:15 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:15 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:15 INFO opendrift:2202: 2026-05-12 08:21:30.676520 - step 21 of 24 - 1000 active elements (0 deactivated)
12:22:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:17 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:17 INFO opendrift:2202: 2026-05-12 09:21:30.676520 - step 22 of 24 - 1000 active elements (0 deactivated)
12:22:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:19 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:19 INFO opendrift:2202: 2026-05-12 10:21:30.676520 - step 23 of 24 - 1000 active elements (0 deactivated)
12:22:20 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:20 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:21 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
12:22:21 INFO opendrift:2202: 2026-05-12 11:21:30.676520 - step 24 of 24 - 1000 active elements (0 deactivated)
12:22:22 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:22 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
12:22:23 INFO opendrift.models.shipdrift:310: 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
0:00:13.0 total
0:00:00.0 preparing
0:00:12.9 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
0:00:16.6 total
0:00:00.0 preparing
0:00:16.5 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
0:00:13.3 total
0:00:00.0 preparing
0:00:13.2 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
Performance:
52.9 total time
4.4 configuration
0.0 preparing main loop
0.0 moving elements to ocean
48.5 main loop
0.5 updating elements
0.0 cleaning up
--------------------
===========================
Model: ShipDrift (OpenDrift version 1.14.9)
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
-----
Readers not added for the following variables:
horizontal_diffusivity
Discarded readers:
Time:
Start: 2026-05-11 12:21:30.676520 UTC
Present: 2026-05-12 12:21:30.676520 UTC
Calculation steps: 24 * 1:00:00 - total time: 1 day, 0:00:00
Output steps: 25 * 1:00:00
===========================
12:22:38 INFO opendrift:4768: Saving animation to /root/project/docs/source/gallery/animations/example_shipdrift_0.gif...
12:22:57 INFO opendrift:3191: Time to make animation: 0:00:19.853024
Total running time of the script: (1 minutes 35.012 seconds)