Originally Posted by RandyBC
I use an artificial horizon at home. I've had very little at-sea practice, but from the waters just outside my marina I've got a clear view to the southern horizon. Note that there are plenty of islands and things, but their shores are beyond the horizon, whose distance is less than three miles away (according to 1.169*sqrt(height of eye)). I just bring the sun's lower limb down to the line separating trees from water and that has worked pretty well.