Garmin Reactor 40 Mechanical Corepack, GHC 50
For boats with a mechanical or solenoid steering drive that add Garmin control.
Amazon $2,249.99$2,249.99
The Garmin Reactor 40 Mechanical Corepack, GHC 50 is the better marine autopilot overall, rated 3.2 to 2.8. The Garmin Reactor 40 Mechanical Corepack, GHC 50 leads on features. The Garmin Reactor 40 Mechanical Corepack, GHC 50 costs $350 less ($2,249.99 vs $2,599.99).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Simrad NAC-3 Autopilot Core Pack
A core pack for boats of 33 ft and up that need a heavy-duty drive; add your own control head and drive.
Amazon $2,599.99$2,599.99
Which should you buy?
- Choose the Garmin Reactor 40 Mechanical Corepack, GHC 50 for features (control head in the box, heading sensor included, NMEA 2000 / SeaTalk ng vs heading sensor included, NMEA 2000 / SeaTalk ng).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every mechanical, cable and solenoid marine autopilot; a clear win is highlighted. How we rank explains each one.
| Factor weight | Garmin Reactor 40 Mechanical Corepack, GHC 50 | Simrad NAC-3 Autopilot Core Pack |
|---|---|---|
| Overall rating | 3.2/5 | 2.8/5 |
| Value 30% | 32 $2,249.99 for the pack | 25 $2,599.99 for the pack |
| Capability range 30% | 50 boat size and cylinder range not published (neutral score used) | 37 boats from 33 ft |
| Features 25% | 75 control head in the box, heading sensor included, NMEA 2000 / SeaTalk ng | 50 heading sensor included, NMEA 2000 / SeaTalk ng |
| Power draw 10% | 50 standby draw not published (neutral score used) | 50 standby draw not published (neutral score used) |
| Warranty 5% | 0 1-year warranty | 0 warranty not published, scored as none |
Specifications
| Garmin Reactor 40 Mechanical Corepack, GHC 50 | Simrad NAC-3 Autopilot Core Pack | |
|---|---|---|
| Capability | ||
| Steering type | Mechanical | Mechanical |
| Boat size | - | 33 ft and up |
| Pack type | Core pack | Core pack |
| In the pack | ||
| Contents | Reactor 40 course computer, GHC 50 autopilot instrument (mechanical, retrofit or solenoid drive sold separately) | NAC-3 computer, RF25N rudder feedback unit, Precision-9 compass, NMEA 2000 starter kit |
| Control head | GHC 50 touchscreen | - |
| Control head included | Yes | No |
| Drive or pump included | No | No |
| Heading sensor | Solid-state 9-axis AHRS | Precision-9 solid-state compass |
| Rudder feedback unit | - | Yes |
| Electrical | ||
| Supply voltage | 12 V | 12/24 V |
| Max drive current | - | 30 A |
| NMEA 2000 / SeaTalk ng | Yes | Yes |
| Support | ||
| Warranty | 1 year | - |
| Released | 2022-06 | - |