gps-guides

Watch Choice

COROS watches have been popular on gps-speedsurfing.com since their approval in 2020. This was off the back of Locosys devices becoming scarce / discontinued and a suitable alternative was desperately required at the time.

During 2024 there were extensive evaluations of comparable Garmin watches and several models were identified as being suitable for watersports and the speedsurfing community. These models include the Forerunner 255 and fēnix 7 series.

Many of the more recent Garmin watches are well suited to watersports, but acceptable GNSS accuracy / precision is limited to a selection of the Garmin watches released since 2022 / 2023. This page is intended to be a quick summary.

GNSS Chipset

The GNSS chipset is the primary limiting factor when it comes to the accuracy of GPS watches. Additional factors include the antenna design, GNSS firmware, watch firmware, user settings and activity mode / watch app.

Various popular watches from Garmin use a Sony GNSS chipset which prioritizes low power usage over accuracy. The Sony-based watches (e.g. fēnix 6 and Instinct 2) have a number of inherent accuracy issues:

• Identical speeds being repeated several seconds in a row, sometimes for more than 15 seconds!
• Big spikes after loss of lock, especially when the watch is submersed during a crash or launching / landing.
• Speeds that are too high (or low) even during normal usage, especially in the non-Doppler data.

The newer Garmin models use an Airoha chipset. These can produce good quality speed data with appropriate watch settings, and activity mode. They can also be somewhat unreliable / inaccurate if you get these things wrong, hence this advice / guidance!

A full list of Garmin watches that use an Airoha GNSS chipset is available on GitHub but includes:

• fēnix 7 / fēnix 7 Pro / fēnix 8 / fēnix E
• epix (Gen 2) / epix Pro (Gen 2)
• quatix 7 / tactix 7
• Instinct 2X (not 2) / Instinct E / Instinct 3
• Forerunner 165 / 255 / 265 / 955 / 965
• Enduro 2 / Enduro 3
• vívoactive 5
• Venu Sq 2 / Venu 3

General Features

There are a lot of Garmin watches to choose from and I intend to write an article on this topic.

Pertinent differences between the watch ranges:

• Display type
  • MIP or AMOLED
• GNSS chipset
  • Multi-band compatibility
• Watch size
  • Several watch ranges come in 42 / 47 / 51 mm
• Battery life
  • Bigger watches typically have longer battery life
• Ruggedness
  • e.g. fēnix > Forerunner > vívoactive
• HR monitor
  • Elevate 5 sensor (e.g. fēnix 7 pro) > Elevate 4 sensor (e.g. fēnix 7)
• Buttons and / or touchscreen
  • Touchscreens are not ideal when wet - e.g. vívoactive or Venu

These differences might help your to choose a watch that is best suited to your own requirements and budget.

Recommendations

Bearing in mind what was said about the GNSS chipset it is advisable to choose a Garmin watch that uses an Airoha chipset, if you are to avoid getting spurious speeds. You can find the GNSS details for all of the different Garmin watches on GitHub, if you are unsure about a specific model.

You should also choose a watch that has a good watersports application available on the Connect IQ store. I would recommend choosing APPro which has undergone a lot of development in recent months, easy to install, and will give you a great experience on the water.

A great all-round watch at a reasonable price is the Forerunner 255 which currently costs around 200 EUR and has already been approved by GPS-Speedsurfing.com and GPS Team Challenge. It is made of a lightweight fibre-reinforced polymer, waterproof and produces good data.

It is also worth considering the fēnix 7 and epix (gen 2) models which have been discounted, ever since the release of the fēnix 8 in October. The fēnix 7 has a MIP display and epix has an AMOLED display, but aside from the displays the various models in the ranges are directly comparable.

The fēnix 7 and epix (gen 2) are much more rugged than a Forerunner. It would also be beneficial to choose a model that supports multi-band GNSS, as some of the cheaper models are single-band. The Fenix 8 is comparable to a fēnix 7 pro sapphire / epix (gen 2) pro sapphire, but with dive capabilities and voice features.

Next Page

Watch setup

• Firmware, watch settings, and applications