Oak Island is a water access geocache. You will need a small boat to reach it.
This geocache is actually on Hardy Island, very close to Oak Island, just north of the narrows between the two islands. There is a small cottage on Oak Island, so the cache is on Hardy Island, out of sight of any cottagers. Remember to check wind speeds before venturing out on the water, and always carry with you everything you need to make it legal - 40 feet of rope, a floating flashlight, a whistle, bailing bucket and life jackets.
As with all my water geocaches, please check wind speed before you head out. This section of the Trent River is called Seymour Lake because it opens up into the size of a small lake. There is usually a west wind, and sometimes it can be very strong, which could make paddling a small watercraft dangerous. Other times, the lake can be calm and peaceful. There is a slight current in the Trent River, but you won't notice it in most places in Seymour Lake. If the predicted wind speed is going to be higher than 15 kms, you shouldn't go in a canoe or kayak. Choose your weather wisely.