The Virb X and Virb XE will be priced at £239 ($349) and £319 ($466) when they are launched in the summer.
Both models are waterproof to a depth of 50m without a case, and can capture "action data" such as speed and a G-force using bespoke system G-Metrix which can then be overlaid on the footage itself.
The market is currently dominated by top seller GoPro.
Garmin launched its first action cam, Virb, in 2013. Sony, Polaroid, HTC and Xiaomi are among other tech firms offering rival devices.
Users of the higher-end Virb XE can manually control advanced settings including white balance, sharpness, colour profile and exposure levels.
The XE also shoots video in high definition quality of either 1440p/30fps (frames per second) or 1080p/60fps, with the cheaper X version offering 1080p/30fps or 720p/60fps.
Both models can capture stills images at up to 12 megapixels and have wi-fi and bluetooth connectivity.
GoPro meanwhile announced a partnership with broadcast equipment manufacturer Vislink which will enable its Hero 3+ and Hero 4 models to broadcast high definition wireless video for the first time.
