Marine Loran Systems were long-range navigation aids using radio signals for precise positioning. They provided hyperbolic navigation by measuring time differences between signals from fixed stations. LORAN was largely replaced by GPS but was crucial for maritime navigation before satellite systems.

Marine Loran Systems (Loran-C) typically operate at frequencies of 90-110 kHz, with a range of up to 1,000 nautical miles. They use ground-wave propagation for accuracy within 0.25 nautical miles. The system consists of transmitter stations with power outputs ranging from 100 kW to 4 MW. Antenna heights vary from 200 to 400 meters. Materials include steel towers and copper wiring for conductivity.

Navigation Systems (GPS, GNSS) operate at L-band frequencies (1.1-1.6 GHz), with accuracy within 3-5 meters for standard GPS and sub-meter for differential GPS (DGPS). Receiver sizes range from handheld (10x5x2 cm) to ship-mounted (30x20x10 cm). Materials include aluminum casings and silicon-based circuitry. Buoyancy is not applicable as these are fixed or portable devices.

For marine buoys used in navigation, sizes range from 1-10 meters in diameter, with buoyancy calculated based on displacement (500 kg to 5,000 kg). Materials include polyethylene, steel, or fiberglass. Viscosity and grade are not applicable to these systems.