Maritime Zones Explained: The Boundaries of Our Seas

The concept of maritime zones is a cornerstone of international maritime law, defined primarily by the United Nations Convention on the Law of the Sea (UNCLOS). These zones determine the extent of a coastal state’s rights, responsibilities, and jurisdiction over the waters and resources adjacent to its shores. Background • Maritime zones were established to resolve disputes over navigation, resource ownership, and national security. • Boundaries are measured from a country’s baseline (usually the low-water mark along the coast). • The key zones include: • Internal Waters – full sovereignty like land territory. • Territorial Sea – up to 12 nautical miles. • Contiguous Zone – up to 24 nautical miles. • Exclusive Economic Zone (EEZ) – up to 200 nautical miles. • Continental Shelf – may extend beyond 200 nautical miles depending on natural features. Purpose • Internal Waters – treated like land territory, full state control. • Territorial Sea (12 nm) – authority over navigation, resources, and law enforcement. • Contiguous Zone (24 nm) – enforcement against smuggling, illegal entry, and security threats. • Exclusive Economic Zone (200 nm) – exclusive rights to explore and exploit resources (fish, oil, gas). • Continental Shelf – rights over seabed resources even beyond EEZ. Importance • Safeguards national security and territorial sovereignty. • Ensures sustainable use of marine resources (fisheries, oil, gas). • Provides control over shipping routes and trade lifelines. • Strengthens sovereignty in disputed waters (vital for nations like the Philippines). • Globally, reduces conflict, promotes order and cooperation, and protects the marine environment.

VHF Marine Radio Channels

This VHF Marine Radio Channels guide presents a clear and practical overview of how Very High Frequency (VHF) radio channels are organized and used in maritime communication. It is designed to help seafarers, maritime students, and industry professionals quickly understand the correct use of each channel in daily operations and emergency situations. At the center of the guide is Channel 16, the internationally recognized channel for distress, safety, and calling, highlighting its vital role in emergency alerts and initial contact between vessels and shore stations. The diagram groups channels according to their operational purpose, including search and rescue (SAR), ship-to-ship safety information, port operations, commercial vessel communications, professional fishing vessels, recreational vessels, and maritime safety organizations. It also identifies channels dedicated to Digital Selective Calling (DSC) and VHF repeaters, supporting efficient distress alerting and extended communication coverage. Color Coding Guide: • Blue channels – Designated for ship-to-shore communications • Red channels – Used primarily for ship-to-ship communications • Black channels – Suitable for both ship-to-shore and ship-to-ship communications Overall, this guide serves as a reliable reference for proper VHF radio use, reinforcing international maritime communication standards while promoting safety, clarity, and effective coordination at sea.

Understanding Ship Draft

Ship draft is the vertical distance between the waterline and the lowest point of a vessel’s hull, usually the keel. It indicates how deep a ship sits in the water and is a critical factor in safe navigation. Draft changes depending on the vessel’s load, including cargo, fuel, ballast, fresh water, and provisions. A deeper draft means the ship is heavier, while a lighter ship has a shallower draft. Understanding draft is essential when entering shallow ports, canals, rivers, or during berthing, as insufficient water depth can lead to grounding and structural damage. There are different types of draft. Forward draft is measured at the bow, aft draft at the stern, and mean draft is the average of both. These measurements help officers assess trim, stability, and compliance with port restrictions. Draft also affects a ship’s speed, fuel consumption, and maneuverability, making accurate monitoring vital for efficient operations.

Fouling

Fouling in the Engine Room Fouling inside heat exchangers, piping and machinery is a persistent threat to vessel reliability, fuel efficiency and safety. Left unchecked, deposits and films build up on internal surfaces, reducing heat transfer, increasing pump and compressor loads, and accelerating corrosion. Below we explain the six common types of engine-room fouling, their root causes, operational impacts, and practical prevention measures every chief engineer and technical manager should know. Types of fouling 1. Scaling Mineral salts precipitate from hard water (e.g., calcium or magnesium salts) and form hard, insulating layers on heat-transfer surfaces. Scaling reduces thermal efficiency and flow, increasing fuel consumption and risking overheating of machinery. 2. Particulate fouling Suspended solids sand, rust particles, paint flakes or sediment settle and accumulate in piping and exchangers. These deposits obstruct flow paths and erode components, leading to frequent filter replacements, higher head loss and reduced system performance.