If a human piloting a craft disappeared, a robot would disappear. However, if you're going to experiment, it's best to use a robot so you're not risking human life.
Have you tried looking at the Bermuda Triangle with Google Earth?
Now I'm all interested in the technical aspects of making an informative bot, under the assumption that anything that enters the Bermuda Triangle goes haywire and disappears.
You can tether it to something. The tether can furthermore be optical wire or something so a signal is constantly bounced back off the robot so you know A. how far away it is and B. it's there and C. if the signal suddenly starts bounding back right at the border of the triangle. The tether could attach either to a station on land (awfully long tether!!!) or to a robot-controlled ship that's a good distance away from the triangle, because you don't want a manned ship to get dragged in.
You can watch the robot with satellites and radar.
And um yeah, you could go the camera route. You can have it remote-controlled, but if there's an issue with signal interference, it'll have to move on its own. Hmm, it can't be trusted to navigate by magnetic poles... or to follow a signal outside the triangle... Maybe the best thing to do is choose a calm day, and design it so all it can do is move forward in a straight line??? (this wouldn't be a robot so much as a motor surrounded by the proper shape of wood that has a camera mounted on it.)
I really have no idea about the nature of the triangle, though. I would think that if everything got screwed up in that area all the time, there would be huge government programs going on to figure it out. I bet that in reality, craft pass through it all the time. There's only a few stories of mysterious disappearences.