AtoBviaC Ltd offers two leading products for calculation of marine distances: the Online Distance Tables and an offline counterpart for Windows PC, PortToPort. These products have been developed over many years and several iterations to provide an easy-to-use and powerful interface for calculating marine distances using our Distance Tables. The products are kept up-to-date with releases usually every 2 to 3 months, so that distances provided remain accurate despite worldwide change.

When used on a machine without an internet connection, PortToPort requires some user action in order to be kept up-to-date.

The two versions offer virtually identical levels of functionality. Differences are primarily related to the areas of installation and licensing. While PortToPort is limited to use on Windows, the Online Distance Tables are available to both Windows and Mac users.

The Online Distance Tables application is based on Microsoft Silverlight technology and requires Version 5 or higher, which the application will attempt to install if necessary when used.

Due to the age and unsupported status of Silverlight, some web browser software vendors have recently begun cutting support for the technology. If this applies to your chosen web browser, then unfortunately you will need to access the Online Distance Tables using another browser (on Windows you can use Internet Explorer; on Mac you can use Safari). Please be assured that we are working on updating the Online Distance Tables to newer technology.