First gap on the right is fairly safe. RHBH throws tend to get wet if a tree is hit. RH flick shot or LHBH is best bet - get up on the bank for an easier approach.
In the A position, the pin is straight up the left lane. In the B position, the smart play is to shoot for the A position and leave yourself with a 40-50 foot putt (easy 3). The harder shot to the B-position pin is to split the large trees about 1/2 way up the fairway and glide to the right side.
There are three lines of approach:
1) Left lane is a flick shot or a slow straight to turn backhand.
2) Center lane is a slow straight to turn backhand.
3) Right lane is a quick turn backhand that glides out with a fade finish.
Jake suggest avoiding the left side of the fairway, however, if you get far enough past the left side tree line, you will actually have an open approach to the pin!
If you pump your disc too hard it has a good chance of getting taken by the wind or going into the river behind the pin. The river is always cold and moving fast. It get pretty deep in the spring.
Watch out for discs! 18 was added after the rest of the course and is right between 12 and 13. Consequently, 18's fairway is used by players playing both holes as an "alternate approach" which can lead to close calls.
If your disc ends up heading towards the river, there are several natural "safeguards" that can hide your disc and make you think it's been lost in the drink. First, there are usually a ton of dead leaves that will slow down and "eat" a disc once you go right of the fairway. Second, there are fallen logs lining the edge of the cliff that collect leaves and can simultaneously catch and bury a disc. Finally, if you disc does make it to the river and you can't initially see it, check under the big log (with the big roots) and you'll likely find several caught discs (my record is 4).