Riviera Astra BAS1 4″ overhead-mount magnetic compass is a liquid-filled magnetic steering compass for motorboats and other vessels where the compass needs to be mounted in the ceiling or canopy above the helm station. This black BAS1/AV variant features a black compass card and is designed for high-speed vessels traveling at speeds over 25 knots.
The overhead placement utilizes an otherwise unused surface and frees up space on the dashboard for displays, control levers, and electronic instruments. The compass features direct front reading, a red lubber line, and a black compass card with 5° graduation. The apparent reading diameter is 4″/100 mm, while the physical compass card diameter is 84 mm.
The liquid-filled compass mechanism features internal gimbaling and a dual-axis system, which stabilizes the reading during rolling and pitching. The design includes two magnets with a magnetic moment of 0.270 A·m², EXXSOL D80 compass fluid, an anti-glare screen, universal balancing, and built-in compensation adjustment.
The housing is made of fiberglass-reinforced nylon, while the spherical bowl is made of polycarbonate. The compass features blue LED lighting for 12 V. The manufacturer number is 62.00854.01, and the compass is manufactured and hand-assembled in Italy.
For flush mounting, the external flange dimension is 168 mm, the cutout dimension is 126.3 mm, and the mounting depth is 64 mm. Once installed, the visible protrusion below the mounting surface is 58 mm, resulting in a total vertical dimension of 122 mm. Therefore, sufficient space must be ensured both above and below the mounting surface.
The Astra 4″ BAS1 type is RINA type-approved as a Class B magnetic compass under EC Type Examination, Module B, certificate MED208723CS, valid until June 19, 2029. The type testing includes ISO 1069:1973, ISO 25862:2019, and IEC 60945:2002 including Corrigendum 1:2008. Individual MED/Wheelmark certification is not automatically included with a standard stock unit but must be ordered separately and linked to the serial number of the compass series. The compass is 100% repairable, supported by original spare parts, and comes with a 3-year warranty. An optional black reverse ceiling housing with manufacturer no. 62.00896.00 is available as an Astra accessory, but is not required for standard flush mounting.
Key featuresHigh-speed version for vessels over 25 knots
Flush overhead mounting above the helm station
Black housing and black compass card with 5° graduation
Direct front reading with red lubber line
4″/100 mm apparent reading diameter
Internal gimbaling and liquid-filled mechanism
Blue LED lighting for 12 V
Cutout dimension 126.3 mm and mounting depth 64 mm
Fiberglass-reinforced nylon and polycarbonate
RINA type-approved BAS1 construction
