Timex Men's TWSA09100 Quartz Watch £16.79 (Prime) / £20.78 (non Prime) @ Amazon

Free delivery for Prime members or orders over £20, otherwise £3.99

Amazon are playing their 'price drop TV' games again with this watch. The price hasn't yet reached the all-time low of £15.17 that it hit just after Christmas, but it's heading that way and I believe it's currently the cheapest Indiglo watch available.

It's 43mm diameter (without crown), 13mm thick and 80+g in weight, so quite a chunky watch. Black sunburst dial, luminous hands, date window and Indiglo.
The compass bezel is fixed and purely decorative. It has a dark grey 'weathered look' finish.

Note: comes on a nice supple suede leather strap, not the fabric strap shown on Amazon.

The same watch but with a brown strap (T49991) is currently around £50. Go figure.