Just recently we completed a 3 week 400km, (250 miles) BC west coast Gulf Island sailing trip during wonderful weather and fair winds. Longest leg was 27nm from Clam Bay via Portier Pass to Mc. Donald Beach located approx. 5 km up the North arm of the Fraser River.
I have used the iPad for the past 3 seasons. Make sure that you have it in a water proof system. (haha) most are water resistant. Add in the new in app purchase of NAV+. this gives you a year of unlimited updates and SonarCharts.