Under the seabed, huh? I don't know why, but I feel safer flying. If anything happened, I would think there is at least a chance I could pop up from under the water (although I don't know how deep the channel is), but to try and get out from somewhere not only underwater, but under 150' of seabed, I would think even MacGuyer couldn't make it.

There must be others that feel this way, although the chunnel has been around for awhile, so it is probably old hat to most by now.