[Malcolm]

I have SkyPortal on an Android phone, and Stellarium on a laptop. Both return the same information on a selected object. ie: Alt/Az.
Last night I attempted a two star alignment. First star chosen was Acrux. Found, centered ok. The second star chosen was Spica. The Synscan hand-piece said it was at Alt 33. SkyPortal placed it at 55. So I aligned it on what I thought was Spica, returned an alignment successful. I then asked for Mars. The tube went to -2, pointing below the horizon, but I could clearly see Mars, well above the horizon. I'd guess around 20 degrees alt. Saturn was also just visible, appearing over the crest of the hill which is west of the house. So I spat the dummy and packed it up.
What went wrong? I realise that to do an alignment you need to know the sky. I'm at a pretty dark site here, I can clearly see the Milky Way, and using the phone app isn't too hard. However trying to find something under magnification, the finder or the eyepiece is not so easy.