Tacktick Micro $499 - small, compass and countdown timer functions only, bulletproof - no backlight, batteries are not replaceable

Velocitek - $499 - countdown timer, speed, vmg, compass, distance to starting line, downloadable data tracks, replaceable batteries, as more features are being added, you can update your unit's software to the latest version - no backlight

TackTick Race Master - $999.99 - countdown timer, compass, header/lift indicator, backlight, replaceable batteries

I'm a fan of the micro for bouy racing and Velocitek for distance racing