FOR PARTS/REPAIR – although the automatic movement keeps accurate time over an approximate 38 hour power reserve period the date wheel is finicky as it will manually roll over but gets hung up when trying to do so automatically on its own. Given this and considering the movement’s unknown service history a complete overhaul is required. This seldom seen vintage 1970’s Avia Marino 20 ATM diver has a blue “T SWISS MADE T” signed dial that is in lovely but not perfect condition as it shows age-related wear. When natural light hits the dial at certain angles, as seen in several of the pictures, the navy blue morphs into a lighter blue hue. The lume, which remains fully intact and emits a quick burst glow on only the dial after being exposed to bright light, has aged gracefully. Bezel, which shows wear and rotates bidirectionally with an appropriate amount of tension. The all stainless steel. Case shows honest wear with no visible signs of oxidation. The outer edge of the case back is stamped “STAINLESS STEEL – WATERPROOF 20 ATU – ANTIMAGNETIC – INCABLOC – AUTOMATIC” with “15033” stamped along the inner edge. The crystal shows scratching. While I normally shows pictures of the movements of watches I put up for sale I’m unable to open the case back on this watch. The 17 jewels automatic movement with semi-quickset date function runs strong and keeps accurate time. However, while the date wheel will manually roll over it gets hung up when trying to do so automatically on its own. When this happens I’ll manually move the hour hand several full revolutions (tends to take three) to get the date wheel to roll over and align properly. When the date wheel finally rolls over it does so to the date that it should have been had it rolled over automatically on its own. This is illustrated in pictures 10 and 11, respectively. The semi-quickset date function works flawlessly by manually rolling over a new date and then moving the hour hand repeatedly between the 20.5 and 24 hour marks until the desired date has been reached. After recently winding the signed, non-screwdown crown 39 full revolutions the movement had a power reserve of approximately 38 hours. The crown winds smoothly. Given the date wheel issue and considering the movement’s unknown service history a complete overhaul is required. This watch measures approximately 37 mm excluding the crown, approximately 40 mm including the crown and approximately 19 mm between the lugs. Case thickness, measured from the bottom of the case back to the top of the bezel, is approximately 9.5 mm. Including the crystal case thickness measures approximately 11 mm. Given the finicky date wheel and considering the movement’s unknown service history a complete overhaul is required. As such there are no warranties, express or implied, attached with the sale of this watch. Vintage means old and while my personal belief is that old-school means better quality and workmanship, things can and do go wrong from time to time. For this watch that time is now. Any servicing costs going forward are your responsibility. And please study the 24 high magnification pictures carefully as they are part of the description and serve as an accurate representation of the condition of this watch.