I've been dormant from this forum for some time, so I apologize for the untimely response, but I feel I should jump in real quick.
I'm perhaps one of the most "seasoned" OffCourse users, having fired through approximately 17,000 markers so far (just 2 users - my ski partner and I). The small Klein level was something I came up with and shared on a different thread here years ago. There was one mention of the occasional errant fire (too wide), I believe from @Windsurfnut. Someone else on the forum hit it on the head when he suggested that's due to being late on the turn. While driving for a skier using OffCourse, pay particular attention to what the boat is doing while the skier is loading the rope coming out of the turn. There is tremendous torsional pull on the boat at that point, causing it to tilt toward the skier. If the skier is late, OffCourse is firing the next marker when the boat is tilted, causing the next marker to shoot wide. If you get late down course, you are no longer in sync with the device. When I'm skiing good, OffCourse fires somewhere in the early stages of my pre-turn when there is no load on the rope.
Overall, I cannot say enough about this product and the company. It's changed our skiing... oh, and back to the OP - yes - you can see the markers no problem. Glad to hear you bought one and either have already figured that out, or will find out soon.
PM me for any other tips or tricks.