For all of my meads and wines, I rack to secondary when the SG is around 1.010-1.020. That means fermentation is still taking place, so there is still some co2 to protect the wine or mead, but that you can move it off of the gross lees and allow it to finish. At that SG, there should be plenty of yeast in suspension to continue the fermentation. Often the movement will kick up more fermentation for a little while.
Once it's at FG, I top up (allowing minimal headspace) and allow it to clear. I rack only when there are lees about 1/4 " or so every 60 days. If there is a light dusting of lees, I let it go a little bit longer than 60 days. If there are no lees, then I leave it alone and just check the airlock once in a while.
Certainly, sweet meads can finish at 1.000 or above, depending on OG and yeast type. With an OG of 1.081 or so, I'd expect it to finish pretty dry, though.