1. There are certain circumstances when magnetic compasses and gyrocompasses are unreliable. 2. Above 85�N both magnetic compasses and normal gyrocompasses become inaccurate. 3. A special gyrocompass built by Sperry Rand was installed shortly before the journey. 4. A gyrocompass , employed for navigation of seagoing vessels, finds the geometric north. 5. GPS compasses share the main advantages of gyrocompasses . 6. Magnetometers, and substitutes such as gyrocompasses , are more stable in such situations. 7. The first functional gyrocompass was patented in 1904 by German inventor Hermann Ansch�tz-Kaempfe. 8. The tail vertical rudder meter set a vertical gyrocompass to control the vertical tail rudders. 9. The submarine was fitted with the first naval periscope and the first naval electric gyrocompass . 10. Her navigation equipment included wireless direction finding, an echo sounding device and a gyrocompass .
Mobile