We have been using Apple’s iPad with Navionics charts for one season. Actually iPad was our primary source of information during the whole Kalmarsund, since paper charts ordered from UK did not arrive in time and our Garmin plotter did not cover this area. We had also a PC laptop with Swedish and Danish charts as a backup. I have also previously used minilaptop as a chart plotter, but I feel that the iPad outperforms minilaptops in many ways:
1) iPad 3G model has a built-in GPS so it can be used as a chart plotter without any external GPS input. GPS seems to be very accurate since we have not noticed any discrepancy with our Garmin GPS.
2) Navionics Marine HD charts are very inexpensive for iPad, compared to cost of the charts for normal chart plotter. The charts are comparable to Navionics Gold charts, which are used in plotters.
3) iPad uses less power than a normal laptop and has a battery capacity of about 10 hours. What I most like about iPad is that it can be switched on from the standby mode within a few seconds. However finding the GPS signal can take some time. Often one needs the plotter to check some details so it is switched on only for about a minute or so at a time.

4) Using the touchpad for zooming and moving through the chart is very handy. iPad is portable, so it can be used anywhere. For example, during the off-watch skipper can use it to check the position, speed and course of the vessel.

Weak points
iPad has not been designed for maritime use so obviously, it has its weak points compared to the chart plotter:
1) First of all it is not water- or shockfproof so one must be cautious when using it in a moving boat. It would be good idea to have some kind of stand or special case where iPad could be mounted when not in use. We have it in its normal storage case in the cockpit in good weather. In bad weather it can only be used indoors.

2) iPad has a glossy screen and thus it can be difficult to see the chart in bright sunlight.
3) The Navionics software crashes occasionally. It happens usually when scrolling through the map too fast. However, iPad usually recovers quickly and the software can be restarted immediatelly.
4) The Navionics mobile interface is stripped down. For example routes cannot be saved and there are no waypoint or MOB-functions.

We have Navionics Europe HD -application which costs around 50 € for iPad. However, sea areas of Denmark and UK are excluded from this application, so they need to be purchased separately. Maps are downloaded to the iPad’s memory so there is no need for internet connection when using the application.
/Antti & Minna

Cover photo:  Press image from Navionics
Navionics/Google Overlay -picture from here
By the way, we have written a blog post on waterproof tablets as well!