Import gpx and kml and export gpx - v2.2.90

New features

  1. GPX and KML files can now be imported en masse. Drag and drop one or more files (or click on the input field to get a file open dialog). You can either add them all to the existing Trip, or create a new trip.
  2. Added Export of loaded trip to .gpx file (in Downloads directory). At present, route departure time and speed are not included. I’m trying to figure out which of the numerous competing .gpx extensions to support. If you have any requests or advice on this topic, please let me know.

Bug fixes

  1. Fixed a bug in “realtime” timebase.

Earth, sun, and moon - v2.2.62

New features

This is mostly a fit and finish release. Lot’s of UI and perf improvements plus a new display of relative positions of earth, sun and moon. This animation, like everything else in DeepZoom is linked to the timebase. The timebase is accessed by clicking on the time readout at the lower center of the screen.

Find trips in View - v2.2.3

New features

  1. Added “Find” to Trips page. This will show a list of all public trips within the current view. Filters are available for “power”, “sail”, “kayak”, and “swim” along with sorting by name, length, duration, and stars.
  2. Added trip id to url so forward and back browser buttons work.

Bug fixes

  1. Fixed longstanding bug which could cause hangs, especially on Cordova demo trip.

Trip: Columbus sails to America in 1492

Historical pilot charts

Pilot Charts show probabilities of wind strength and direction for a particular location and time, to help plan optimal sailing routes. Historically, these charts were derived by manually collating the logs of thousands of vessels transiting the oceans over the last few hundred years.

Below is an excerpt from a traditional pilot chart for a portion of the southern Pacific ocean during the month of February. Each windrose covers a 5°x5° area. The length of the barb indicates the percentage of time the wind blew from that direction, and the barb style indicates the strength of the wind.

DeepZoom pilot charts

DeepZoom does the same thing on steroids. Instead of using the ship historical data, DeepZoom uses satellite derived wind strength and direction information displayed as a polar histogram.

The Pilot Charts layer lets you plan a route based on historically measured wind speeds and directions. This layer shows a probability windrose on a color coded background. The background shows mean historical wind speed along with arrows showing mean wind direction for each 14 day period.

Superimposed on this background is a windrose which shows the percentage of time the wind is blowing from each of 16 cardinal/secondary/intercardinal directions. The length of each bar shows the percentage of time the wind blows from that direction averaged over a 14 day period. The length of the colored rectangles within each bar indicates the percentage of time the wind blows with each velocity range.

Columbus trip 1

Here’s a trip showing how Columbus travelled to the Bahamas on his first voyage. The bar from due east ending in the number “42”, indicates that the wind was blowing from that cardinal direction 42% of the time. The wind was under 20 knots about 40% of the time, and there was an easterly component virtually all the time.

Columbus was likely sailing straight down wind most of the westward voyage.

Try it:

Another cool polar histogram example

Entropy levels of 100 world cities by the orientation of streets.
Most ordered streets: Chicago, Miami, & Minneapolis.
Most disordered: Charlotte, Sao Paulo, Rome & Singapore. Paper:

city street orientation graph


Pilot Charts - v2.1.55

New features

  1. Includes “Pilot Charts”, which is enabled on the layers panel. Shows a historical, satellite derived wind strength and direction probability windrose.
  2. Added scripting support for pilot chart opacity.
  3. “Exit Demo” now does an auto Trip.New, clearing out any existing trip (whether demo, or user created).

World Magnetic Model - v2.1.37

New features

  1. You can now show the following for each leg of a route:
    • route leg length
    • Magnetic compass heading
    • True compass heading

Each of these can be enabled/disabled individually (see the settings page). The magnetic course value is derived from the World Magnetic Model (currently WMM2020, valid from 2020-2025).

Bug fixes

  1. MAJOR performance improvements in route editing on phones and mobile devices.

Trip: Bike the San Juan Islands

DeepZoom was designed for trips on the water. But you can also use it for driving, hiking, and biking trips.

Here’s an example of a multi-modal trip, biking from Blaine, WA through the San Juan Islands. Each terrestrial leg is a separate route, and each ferry ride is a separate route.

Try it:

To create terrestrial routes, first define start, end, and waypoints as you normally would with aquatic trips. Then on the routes page, change the mode of transit (driving, walking, biking), and your route will be converted to the new mode.

If you need to change the route, the easiest way is just to convert back to the original “great circle” or ship/plane navigation mode, add or change waypoints, and then convert back to driving, walking, or biking.

Trip: Cape Cod Canal

DeepZoom works worldwide for trip planning. Here’s an example of transiting the Cape Cod Canal when the current is flowing at peak velocity.

When you save a trip in DeepZoom it resides in the cloud. You can specify whether it can be viewed by the general public or only by persons with whom you share a link.

In either case, just copy the link and share it with anyone you want:

Trip: Wellington to Picton New Zealand

New Zealand is one of the few countries in the world which makes their nautical charts available for free. Others include the USA, Brazil, and Argentina. Here’s a good listing of the worldwide nautical publishing agencies. And the USA is the only country which has placed in the public domain the tide and current harmonics needed by DeepZoom to create animated current displays.

Instead, each country has a semi-functional website where you can license charts and download them in a bewildering array of formats. Or you end up just paying your charting application to handle the licensing on your behalf.

Since this is a low budget operation, I can’t justify the rather exorbitant licensing cost for charts from each national government publishing entity. If DeepZoom ever grows up to play in the big leagues, it will need to face this issue.

Try it:

DeepZoom 2.0 is ON THE AIR!

Watch the video:

Some history

I started the original incarnation of DeepZoom sometime around 2008, mainly to learn web technologies and because I couldn’t find a good web visualization of tides and currents.

While sailing and kayaking in the Pacific Northwest and Alaska, I would sometimes find myself making little or no progress against a substantial tidal flow, so it’s been easy to become obsessed by the topic of tides and currents. Plus, I spent formative years of my youth with the wharf rats under the industrial docks in Everett, Washington, where tides were the main event.

The original version of DeepZoom was built with Silverlight, and then a version followed for Windows Phone. The Windows Phone version was actually kind of nice, responsive, and presenting a reasonably easy environment for me, the developer. But overall - What a fiasco!, having both technology platforms fail so spectacularly. Thanks, Microsoft!

Eventually I rebuilt everything using web technologies like Bootstrap and D3. It worked well enough and then I got distracted imaging neurons at the Allen Institute for Brain Science for a few years.

Being largely homebound for the duration of Covid-19 provided an opportunity to rework DeepZoom yet again, this time switching to Quasar/Vue as the primary client framework. And then came unbridled feature creep: trips, routes, markers, tracks, pilot charts, wikipedia, and the ability to share trip plans with others.


I’m much indebted to Morgan Conrad for help with wind data wrangling and Chris Mulverhill for Coast Pilot processing.

Where to next?

I’m often at a loss to figure out what features to prioritize next.
I’m just trying to include all of the tools I like to use when planning a voyage of a day, week, or months. If you have any suggestions, I’d love to hear from you on the discussion forum.

Recent Posts

Trip: Columbus sails to America in 1492

4 minute read

Historical pilot charts Pilot Charts show probabilities of wind strength and direction for a particular location and time, to help plan optimal sailing rout...

Trip: Bike the San Juan Islands

1 minute read

DeepZoom was designed for trips on the water. But you can also use it for driving, hiking, and biking trips.