SeaNav app improvement
Pocket Mariner has added an air draught augmented reality (AR) feature to its SeaNav app, which may interest PBO readers. Users can select a SeaNav POI (point of interest) marker for a bridge (or cable) on the SeaNav map view, set their boat’s air draught in SeaNav’s settings and see this as they approach the bridge in AR view mode.
Pictured is one of the three low bridges Pocket Mariner founder and CEO Steve Bennett has to pass beneath on a tidal river around high tide (12m at Springs) to reach the Bristol Channel from his boat’s mooring. With the horizon line lined up with the sea level at the bottom of the bridge, the bold red line shows the height of your boat at the bridge.
The latest Apple iOS now provides Field of View parameters which enables the relative drawing calculations to be done on all devices. The app could also show your boat’s width at the point.
Steve suggests that users ‘calibrate’ their air draught by setting it then viewing their own boat at a distance of 200ft or so. This must only be used as a guide, not solely relied upon, and the captain’s decision to pass under a bridge should be based on their own judgement.
The SeaNav POI feature comes with the free version of the SeaNav app: air draught is now included with SeaNav Pro in-app purchases, priced at £9.99, which adds AR and live ship AIS positions.