Compatible charts
PassagePlus is compatible with the following chart series:
  1. ‣ARCS (Admiralty Raster Chart Service): about 3,000 charts covering the whole world, published by the UK Hydrographic Office.
  2. ‣NZMariner: about 160 charts covering New Zealand and surrounding waters, produced by Land Information New Zealand.
  3. ‣Seafarer RNC: about 430 charts covering Australia and surrounding waters, produced by the Australian Hydrographic Service.
In all three cases these are precisely scanned facsimiles (raster images) of the relevant hydrographic office's official paper charts. On screen, therefore, they appear identical to the paper charts. It is precisely because of their instant familiarity to those accustomed to using Admiralty paper charts, that raster electronic charts remain popular, despite the advances in vector charts.
PassagePlus is not compatible with other raster chart series (such as Maptech) and  is not compatible with vector charts.
The Hydrographic Raster Chart Format (HCRF)
ARCS, NZMariner and Seafarer RNC all use the HCRF chart file format and they are identical in appearance and function. PassagePlus allows you to mix charts from all three publishers seamlessly in one overall portfolio.
In addition to the actual chart image, each chart comes with a considerable amount of other data (metadata) providing information about the chart. PassagePlus allows you to access all this information.
As well as simple things like chart scale and depth units, this includes more complex data such as the georeferencing formulae that allow each pixel in the image to be referenced to a precise latitude and longitude. Colour data allow each chart to be viewed in three different palettes—one for daytime use, one for dusk and one for nighttime.
You also get access to the electronic chart catalogue for the chart service(s) you are using. Using this, PassagePlus helps you manage your charts and see whether they are up to date. It is also used in determining which other charts are related to the one you are currently viewing. Furthermore you can use it to find out whether there are charts available for a given location in addition to those you already own.
All current Temporary Notices to Mariners (NMs) are included. These contain information about matters that have not yet been incorporated into the actual chart image and other general information. PassagePlus allows you to inspect the NMs relevant to the chart you are currently viewing.
Chart updating is an important feature of HCRF. Charts are updated frequently—weekly in the case of ARCS, and monthly for NZMariner and Seafarer RNC. When this happens, rather than issuing an entire new set of files for every chart, an Update CD is provided which updates only the relevant parts of changed files. The Update CD always contains the cumulative updates (if any) for every chart in the series since the last full Charts CD was issued, so you can update less often if you wish yet still be brought fully up to date with a single CD.
Differences between ARCS, NZMariner and Seafarer RNC
As already mentioned, ARCS, NZMariner and Seafarer RNC all use the same HCRF file format, all operate identically when opened and can be mixed freely. The differences lie in how they are distributed and updated:
 
Managing your chart portfolio
PassagePlus provides tools to help you manage your portfolio of ARCS, NZMariner and Seafarer RNC charts and keep them up to date. See Chart Management.
Buying charts
We do not sell charts. Please also read our FAQ section for information on buying / downloading charts.
Charts
ARCS is marketed as two services, ARCS Navigator and ARCS Skipper. The actual charts are identical. The Navigator service is intended for commercial shipping. The price includes a year's worth of weekly updates, and the assumption is that all charts will be updated every week. Once the yearly subscription expires the charts are no longer viewable. The Skipper service is aimed at the leisure market. Charts do not expire and the user buys one-off updates as and when he wishes or can subscribe to a quarter's or year's worth of updates. At present, PassagePlus works only with the Skipper service (not Navigator). Charts and updates are distributed on CD and are available from nautical retailers.
Seafarer RNC is also marketed as two services, the 'Chart' service and the 'Update' service, superficially similar to but subtly different from the ARCS Skipper and Navigator services respectively. The Charts service provides the user with the chart updated to the date of purchase but does not normally provide subsequent updates (although one-off updating is possible for a fee). Charts do not expire. The Update service provides the charts plus a year's worth of monthly updates. Once the update subscription has expired, the charts remain usable at their current state of updatedness (they do not expire, unlike Navigator). PassagePlus works with both the Chart and the Update services. Charts and updates are distributed on CD and are available from nautical retailers.
NZMariner is marketed as a single service. The charts are available free of charge. They were previously distributed on CD, but since July 2008 both charts and monthly updates are downloaded from LINZ's website. Updating is optional. Charts do not expire. PassagePlus works with NZMariner, both with downloaded files and the older CD method.