Ahh, tried to post once and the site seemed to give me an error. Tough to explain, but I will try, if it doesn't make sense, send me a private message with your number and I will call u.
Once you are on the island keep following the main road (basically away from Portland), when the road splits, keep going to the right, inland. You will see tennis court and school on the right side, then road will veer left, keep following. Then, you will see the road splitting again, this time, you will go to the left off the main road. Follow that for a few miles, road will get worse and worse, pavement will end, you will get to a gate, go ahead, the channel that I fish in will be on your right side, but its a long channel, it veers under the road and to your right. There are a few spots to fish around there, place is not that wide, but well worth a try. If you keep driving on that road, you will see a lake on the right, keep driving towards the top, you will the same channel on your left side, quite a few spots there as well, caught fish there as well. Let me know how it goes or if you have any better spots, it seems that area is carp heaven.