WORKHARBOR
Chart a maritime career — free calculators for seafarers, ships, and ports, plus plain-English guides to merchant-marine life, shipping and logistics, and the jobs that keep the world's cargo moving.
From converting knots and planning a great-circle passage to counting cargo in TEU, estimating a ship’s tonnage, building a watch rotation, and tallying qualifying sea time for a certificate, WorkHarbor pairs free hands-on calculators with plain-English guides to merchant-marine life, shipping and logistics, and an illustrated maritime museum. Get the numbers behind a career at sea right.
Maritime Calculators & Tools
Free tools for life and work at sea — knots speed converter, nautical distance and ETA, cargo TEU calculator, ship tonnage, watch-schedule planner, and a sea-time calculator.
Knots Speed Converter
Convert a vessel's speed between knots, mph, km/h, and m/s — the everyday conversion for reading a speed log, a weather forecast, or a passage plan
Nautical Distance & ETA Calculator
Passage time from distance and speed, or the great-circle distance in nautical miles between two lat/long positions, then the ETA at your planned speed of advance
Cargo TEU Calculator
Turn a mix of 20-, 40-, and 45-foot boxes into a total TEU count and physical container total — the maths behind container-ship capacity and terminal throughput
Ship Tonnage Calculator
Gross tonnage from enclosed volume, and displacement and deadweight from length, beam, draft, and block coefficient — the tonnage basics behind a ship's size and cargo capacity
Watch Schedule Planner
Turn crew size and a watch system into a clear rotation — who has the watch and each hand's hours on duty per day, for four-on-eight, six-on-six, or dog watches
Sea Time Calculator
Add up sign-on and sign-off dates across voyages into total sea-service days and months — the qualifying-sea-time tally for STCW certificates and licence renewals
Maritime Heritage Museum
Step into an illustrated museum of ships and the sea — the cargo ships, tankers, and container vessels that carry the world’s trade, the great ports and harbours where they load and discharge, and the lighthouses, canals, dry docks, and traditions of maritime history, each in its own gallery. Get to know the vessels, the ports, and the people behind the work of moving cargo across the oceans.
Tour the museum →From the Maritime Careers Journal
Fresh guides on seafaring life and shipboard work, maritime certificates and sea-service, shipping and port logistics, and the jobs across the merchant fleet, plus plain-language explainers on building a durable career at sea.
The Blue Economy: Exploring Opportunities and Challenges in Maritime Employment
Advanced Fishing And Boating Services Techniques and Methods
Marine Industry Careers Strategies and Implementation
Fundamental Components of Effective Harbour Safety Protocols
The Strategic Pillar of Global Trade: Understanding Harbour Logistics in Modern Supply Chains
The Vital Role of Harbour Services in Modern Maritime Trade and Community Development
Keep Learning
Plain-language explainers on ships and cargo, ports and terminals, seafaring life and watchkeeping, and maritime careers and training — everything you need to read the numbers behind a life at sea with confidence.
Visit the Learn hub →