Marine GPS & DGPS Repair, Maintenance, Supply & Calibration in India
Seanav Marine is India’s foremost technical service authority for commercial Marine GPS and DGPS receiver overhauls, active antenna renewals, differential beacon calibration, and NMEA sensor interfacing for ocean-going merchant fleets.
Seanav Marine delivers certified Marine GPS, DGPS, and GNSS navigation receiver repair, active antenna replacement, coastal differential beacon calibration, NMEA 0183 / IEC 61162 sensor interfacing, and ready stock supply across all 400+ Indian commercial ports and anchorages (JNPT/Nhava Sheva, Mumbai, Kandla, Mundra, Cochin, Chennai, Visakhapatnam, Paradip, Haldia, Mormugao, Mangalore, Tuticorin). Servicing Furuno (GP-170, GP-150, GP-39), JRC (JLR-7800, JLR-7500), Simrad, and Sailor systems, our certified marine electronics engineers attend 24/7 with calibrated RF wattmeters, active GPA antenna replacements, and NMEA analyzers to guarantee sub-meter positioning accuracy, RAIM integrity validation, and zero Port State Control (PSC) downtime.
⚙️ Technical Specifications & Operational Coverage
| Receiver Types | GPS, Differential GPS (DGPS), Multi-GNSS (GPS / GLONASS / Galileo / BeiDou), SBAS (GAGAN / WAAS / EGNOS) |
|---|---|
| Supported Hardware | Furuno (GP-170 / GP-150 / GP-39 / GP-33 / GP-32), JRC (JLR-7800 / JLR-7900 / JLR-7500 / JLR-7700), Sailor / Cobham (6588 DGPS), Simrad (MX610 / MX521A), Samyung (SPR-1400), Koden (KGP-920) |
| Regulatory Standards | SOLAS Chapter V Regulation 19.2.1.6, IMO Resolution MSC.112(73), IEC 61108-1, IEC 61162-1 (NMEA 0183), DGS Directives |
| NMEA Interfaces | IEC 61162-1 / NMEA 0183 ($GPGGA, $GPRMC, $GPVTG, $GPGLL, $GPZDA, $GPDTM) distributed to Dual ECDIS, X/S-Band Radars, VDR, and Class A AIS |
| Antenna Hardware | Genuine Marine active patch antennas (Furuno GPA-017S, GPA-018S, GPA-019S, JRC NNC-4198), RG-214 low-loss coaxial cabling, pre-amplifiers |
| Attendance SLA | Berth attendance within 2 to 4 hours at JNPT/Mumbai, Kandla, Mundra, Cochin, Chennai, Vizag; 24/7 emergency anchorage fly-away dispatch across all Indian roadsteads |
| Differential Beacon | Indian coastal beacon receiver testing (283.5–325.0 kHz) and GAGAN satellite SBAS augmentation tracking verification |
🏷️ Supported OEM Brands & Equipment
Our engineers are equipped with manufacturer diagnostic keys, test software, and genuine spare parts for leading bridge electronics manufacturers:
📋 Standard 5-Step Marine GPS & GNSS Overhaul & Calibration SOP
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Masthead Active Antenna & Coaxial Feeder VSWR Assessment
Inspect monkey island masthead GPS antenna radome for UV micro-cracking and salt water ingress; test RG-214 coaxial feeder attenuation, insertion loss, and VSWR sweep with calibrated RF analyzer.
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Multi-Constellation Satellite Lock & C/N0 Signal Ratio Verification
Measure DC supply voltage (5V/12V phantom power) on coaxial line; verify simultaneous tracking of minimum 8 GNSS satellites with carrier-to-noise density (C/N0) exceeding 42 dB-Hz.
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Coastal DGPS Beacon & GAGAN SBAS Correction Audit
Tune internal beacon receiver to nearest Indian coastal DGPS station; verify demodulation of RTCM SC-104 differential corrections and validate GAGAN GEO satellite lock (PRN 127/128).
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RAIM (Receiver Autonomous Integrity Monitoring) Alert Simulation
Perform RAIM pseudo-range integrity simulation; verify visual/audible caution alarms trigger if positional accuracy protection limit exceeds IMO limits (10m harbor entrance / 100m coastal).
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Multi-Drop NMEA 0183 Buffer Interfacing & VDR Output Check
Verify high-speed serial sentence streaming ($GPGGA, $GPRMC, $GPVTG) across isolated buffer channels to Master/Backup ECDIS, X/S-Band Radars, AIS Transponder, and Voyage Data Recorder (VDR).
🔍 High-Intent Marine GPS Bridge Failures Resolved at Indian Ports
| Reported Defect | Root Cause Diagnosis | Technical Remediation |
|---|---|---|
| ECDIS & Radar Trigger "LOST POSITION SENSOR / NO POS ALARM" | Active antenna LNA preamp failure due to lightning surge, water ingress in coax connector, or blown opto-isolator on RS-422 NMEA output buffer. | Antenna renewal with genuine GPA-017S, RG-214 coaxial re-termination, and NMEA buffer IC replacement at berth within 3 hours. |
| GPS Receiver Fails to Acquire Constellation Fix / Satellite Lock Lost | RF shielding from container gantry cranes, monkey island cable pinching, or depleted internal lithium backup battery on receiver mainboard. | Mainboard lithium cell replacement, cold-start almanac reload, and antenna re-alignment to clear RF blockage. |
| DGPS Beacon Signal Lost / Intermittent Differential Mode | Damaged whip antenna for MF beacon receiver, coastal beacon frequency drift, or grounding corrosion. | Beacon pre-amp overhaul, Indian coastal station frequency realignment, and earthing bonding strap replacement. |
| NMEA Data Sentence Corruption / Baud Rate Mismatch on Bridge Network | Serial port parity mismatch (4800 bps standard vs 38400 bps high-speed) or buffer multiplexer overrun causing sentence dropouts. | NMEA sentence analyzer signal capture, baud rate standardization, and multi-channel serial buffer multiplexer installation. |
Emergency GPS Antenna Renewal & ECDIS Interfacing on 64,000 DWT Bulk Carrier at JNPT
Reported Problem: Vessel scheduled to sail from JNPT Berth 3 on morning high tide; primary GPS receiver lost satellite fix, triggering continuous "POSITION SENSOR LOST" alarm on dual ECDIS and X-Band radar.
Technical Diagnosis: Seanav flying squad engineer boarded at JNPT with RF power meter and spare antennas; diagnosed severe water ingress at the monkey island antenna base with corroded N-type connector, dropping antenna DC bias voltage from 5.0V to 0.8V.
Corrective Attendance: Replaced damaged antenna with fresh stock Furuno GPA-017S active antenna, renewed 25 meters of marine-grade RG-214 low-loss coaxial cable with heat-shrink vulcanized connectors, reconfigured NMEA 0183 output sentences ($GPGGA, $GPRMC, $GPVTG) at 4800 bps, and verified seamless automatic position failover on both ECDIS workstations.
🌐 Strategic Indian Port & Equipment Authorities
Explore specialized technical resources and 24/7 engineer coverage across key Indian shipping hubs:
Mumbai Port (MbPA)
24/7 attendance across Indira Dock, Pir Pau & Mumbai Floating Light (BFL) anchorage.
View Mumbai Hub →JNPA / Nhava Sheva (JNPT)
Fast-track attendance for BMCT, APMT GTI, NSICT & NSIGT container terminals.
View JNPA Hub →Adani Mundra Port
Container berths, West Basin coal terminal, SPM & Mundra Roads anchorage support.
View Mundra Hub →Deendayal Port (Kandla)
Gandhidham depot covering cargo berths 1-16, Tuna Tekra & Vadinar offshore SPM.
View Kandla Hub →Chennai Port (ChPT)
Container terminals CCTPL, CITPL, Jawahar Dock & Kamarajar Ennore attendance.
View Chennai Hub →Cochin Port / ICTT
ICTT Vallarpadam berths, Cochin Shipyard & OPL East-West route launch service.
View Cochin Hub →Visakhapatnam (Vizag)
VCTPL container terminal, ore berths, Gangavaram Port & Dolphin’s Nose anchorage.
View Vizag Hub →Programming Authority
Certified MMSI reprogramming, AIS static data, VHF DSC & EPIRB Hex ID re-coding.
View Programming Scope →Flag Change Package
Turnkey single-attendance reprogramming for ship flag, name & ownership changes.
View Flag Change Scope →Reviewed & Certified by Technical Operations Directorate
Lead Marine Electronics Surveyor & Technical Director · Seanav Marine Pvt Ltd
Master technical oversight for SOLAS Chapter IV & V navigational safety and radio communications. Certified in statutory marine radio surveys, gyro compass meridian calibrations, radar transceiver overhauls, and VDR APT protocols across 170+ commercial Indian ports and anchorages.
❓ Frequently Asked Questions
Under SOLAS Chapter V Regulation 19.2.1.6 and IMO Resolution MSC.112(73), all ships regardless of size must carry a type-approved receiver for a global navigation satellite system (GNSS) or a terrestrial radio navigation system to automatically establish and update the ship's position at all times throughout the voyage.
Our flying squad engineers deploy within 2 to 4 hours to berths across major Indian gateways—including JNPT / Mumbai, Mundra, Kandla, Chennai, Cochin, and Visakhapatnam. For vessels at outer anchorages (such as Mumbai Floating Light, Kandla Roads, or Cochin OPL), we deploy via authorized harbor pilot launches around the clock.
Yes. Our central Navi Mumbai logistics hub and regional coastal centers maintain ready stock of Furuno GP-170, GP-150, GP-39, JRC JLR-7800, active antennas (GPA-017S, GPA-018S, GPA-019S), power supply units, NMEA buffer multiplexers, and RG-214 coaxial cable for immediate port delivery under customs ship-spares-in-transit clearance.
Our technicians utilize calibrated RF spectrum analyzers and NMEA data loggers to test coastal MF differential beacon reception from Indian DGLL beacon stations (such as Uttan, Aguada, Vengurla, Dolphin's Nose) and verify GAGAN SBAS satellite augmentation lock, guaranteeing sub-meter positioning precision.
Yes. Our engineers specialize in diagnosing serial NMEA 0183 and IEC 61162 data communication faults, resolving baud rate mismatches, renewing isolated buffer amplifier modules, and setting up dual-GPS automatic sensor redundancy across ECDIS, Radar, AIS, and VDR systems.