NavList:

I heartily agree, art! I cycled through all sorts of AH lash-ups... front surface mirrors, bowls with everything from floating mirrors, automotive oil, to molasses and Karo corn syrup! Oh, and one of the cute plastic Davis AHs.

Molasses is a great option, but a hassle if spilled. I got the best result (defined as convenience plus reasonable accuracy) by attaching a surface mirror to a plate attached to a surveying tribrach,which I had screwed into a steel plate instead of a tripod so I could set it on a low table).  I even managed to snag several antique K&E black mirror expedition AHs.  In the end I found that, excepting the puddle of molasses,  the stumbling block was getting a reliable level. That and working the leveling screws - nothing except the tribrach leveled out satisfactorily. (Btw, am happy to send pics fo the tribrach setup if anyone is interested)

I also worked my way through several varieties of bubble horizons.  At one point, I had every variation of Plath's bubble horizons, including the legendary firefly.  In the end I donated all of the AH's to our Rumsey Map Center at Harvard along with all but one of my sextants.  I kept my Horizon Ultra (purchased from the legendary Ridge White) and my favorite AH, the Cassens & Plath "Artificial Bubble Horizon."

Oh, another fun one was a Wild Astrolabe attachment which I used on both a Wild T1a and Wild T2 theodolite.  Substituting motor oil for the mercury it was supposed to be used with it.  The stability of a thodolite on a tripod made a huge difference, but in the end, I simply took a noon curve with the theodolite using a Roelofs Solar prism. That works exceptionally well, of course.

My conclusion?  Molasses is reliable, tribrach-and-mirror is less messy, but... nothing beats an ocean horizon!  ;-)