Expedition cruise operators and guides
Plan landings, zodiac cruising and new sites ahead of the season with a clearer picture of what lies below.
Chart GapExplore the Uncharted.
See depths where official charts are blank.
Chart Gap brings together the bathymetry collected by all kinds of vessels, from polar research ships to expedition cruise ships, and layers it with ice and glacier fronts, satellite imagery and seafloor morphology. One rich picture of the seafloor to explore in 2D and 3D, made for researchers and explorers of the uncharted.
Now in beta with the Antarctic Peninsula. Start free in Andvord Bay.
Free account with your email. No card needed.
- 70Multibeam surveys
- SinglebeamCrowdsourced soundings included
- 1987–2025Survey years
- 33Antarctic Peninsula regions
Built on open data from NOAA NCEI, IEDA/MGDS, the Alfred Wegener Institute (via PANGAEA), the British Antarctic Survey, GMRT, GEBCO and IBCSO. Data sources
The map
The seafloor, before you get there.
2D and 3D terrain
Tilt and fly through fjords, banks and channels with the land and ice around them.
Depth colours, contours and soundings
Read the shape of the bottom at a glance, then zoom in for the numbers.
Honest about the gaps
Unsurveyed water is marked as such, so you always know what the data does and does not show.
Every survey credited
See which surveys each area is built from, and how certain each depth is.
Ice, imagery and seafloor shape
Glacier and ice-front positions back to 1843, Sentinel-2 satellite imagery, seafloor geomorphology, ICESat-2 satellite depths, tide models and more.
Who it's for
Made for people who explore beyond the charts.
Yacht skippers
Study remote bays and passages from home, and see where modern surveys exist and where they do not.
Researchers
Browse processed multibeam across cruises in one place, with sources and certainty for every area.
Plans
Start free. Go further when you need to.
Every plan includes the 2D and 3D map. Paid plans open every area we publish.
Prices in US dollars (USD).
Free
For anyone who wants to explore the seafloor, no card needed.
$0email sign-up
Free forever
- Free area: Andvord Bay, in full detail
- 2D map and 3D seafloor view
- Depth colours, contours and soundings
- Survey coverage and source credits
Researcher
For scientists and students working in polar waters. Invitation only - requires .edu email.
$0by invitation
Free for approved researchers
- All areas
- Research data: extra surveys whose licence is not yet cleared for commercial use
- Data exports: 20 per month
- Never charged
Pro
For expedition cruise operators, guides and yacht skippers planning a season.
$199/ month
$199$149/ monthSave 25%
or $149/month billed annually
Billed $1,791 a year
- All Antarctic Peninsula areas, and new areas as they are added
- 2D map and 3D seafloor view
- Depth colours, contours and soundings
- Survey coverage and source credits
Expedition
For operators and teams who want the data in their own tools.
$499/ month
$499$374/ monthSave 25%
or $374/month billed annually
Billed $4,491 a year
- Everything in Pro
- Chart and data downloads: 10 per month
- GeoTIFF, BAG, NetCDF, Olex XYZ, CSV/XYZ and KMZ
- WGS84 by default
Cancel any time from your account. Subscriptions are billed by OSIBOT PTY LTD through Stripe, under the Terms and Privacy Policy.
Where the data comes from
Real surveys, properly credited.
The depths come from multibeam sonar surveys run by research and other vessels and published by national data centres and research institutes. We process each cruise into one consistent grid, add crowdsourced singlebeam tracks from cruise ships and other vessels, and fill the gaps with the global and regional grids GEBCO, GMRT and IBCSO where no ship has surveyed. Every area shows which surveys it comes from.
Around the depths sit the other layers: glacier and ice fronts, Sentinel-2 satellite imagery, the coastline, seafloor geomorphology, gravity-derived depths and land heights. Everything is public data, regularly updated as new surveys and releases appear, and credited in full on the map and on our credits page. It is a tool for planning and exploring, not a chart for navigation. Read why
Bathymetry
- NOAA NCEI / DCDBMultibeam cruise archives: RV Nathaniel B. Palmer, Knorr, Roger Revelle and morePublic data via NOAA NODD
- IEDA / MGDSProcessed RV Nathaniel B. Palmer multibeamCC BY 4.0
- AWI · PANGAEARV Polarstern multibeam surveysCC BY 4.0 / CC BY 3.0
- British Antarctic SurveyRRS James Clark Ross multibeam (UK Polar Data Centre)OGL v3 / CC BY 4.0
- DCDB Crowdsourced BathymetrySinglebeam tracks from cruise ships and FarSounder-equipped vesselsCC0
- GEBCO 2026Global grid used where no ship has surveyedPublic domain
- GMRTMulti-resolution grid of merged ship surveysCC BY 4.0
- IBCSO v2Southern Ocean regional bathymetry gridCC BY 4.0
Other layers
- BAS Sentinel-2 mosaicSatellite imagery of land and iceOGL v3, Copernicus Sentinel-2 data
- SCAR Antarctic Digital DatabaseHigh-resolution coastline (v7.12)CC BY 4.0
- Glacier frontsIce-front positions from PANGAEA, UK Polar Data Centre and DLR IceLinesCC BY 4.0 / OGL v3
- Seafloor geomorphologySeabed features mapped by Geoscience Australia (Post et al.)CC BY 4.0
- Gravity-derived depthsDepth estimates from gravity data (Charrassin et al.)CC BY 4.0
- Copernicus DEM GLO-30Land and ice heights for the terrain viewDLR / Airbus, Copernicus