This guide describes how the Seattle market works. It is general information, not legal, regulatory or tax advice, and it does not indicate that Zeaclub maintains an office in Seattle. Regulatory detail changes — verify against the authority before relying on it.
Seattle at a glance
| Seattle | |
|---|---|
| Competent authority | United States Coast Guard, Sector Puget Sound |
| Compulsory pilotage | Puget Sound Pilots |
| Approach constraint | Long Strait of Juan de Fuca and Puget Sound transit; deep water throughout but a substantial pilotage passage |
| Port state control | USCG port state control regime (outside the MoU structure) |
| Register | US flag for domestic trades under the Jones Act; foreign flags in international trades |
| Principal ports | Terminal 5, Terminal 18, Terminal 30, Tacoma nearby |
| Currency | USD |
| Time zone | PST (UTC-8) / PDT |
What the cluster does
Seattle operates with Tacoma as the Northwest Seaport Alliance, sharing container volume across both harbours. The approach is deep but long — a substantial transit from the Strait of Juan de Fuca — and the port is the principal US gateway for Alaska trades, which run under the Jones Act and have their own seasonal rhythm.
- Northwest Seaport Alliance with Tacoma
- Principal Alaska trade gateway
- Deep water with no draft restriction
- Transpacific and Asian services
Topic guides for Seattle
Sailing Distances from Seattle: Routes, Chokepoints and Voyage Time
How port-to-port distance from Seattle is actually calculated, and the routing decisions that move the number.
Ship-to-Ship Transfer and Lightering at Seattle
Where ship-to-ship transfer happens around Seattle, who authorises it, and what governs the operation.
MTSA Security at Seattle: 33 CFR 104 and 105 in Practice
How US port security law actually applies at Seattle — MTSA rather than ISPS, and what that changes.
Laytime and Demurrage at Seattle: Local Practice and Common Disputes
What actually drives laytime and demurrage exposure at Seattle, and where claims are won and lost.
Pilotage and Berthing at Seattle: Approach, Timing and Constraints
How the approach to Seattle actually works — pilotage, tidal and draft constraints, and the berthing sequence.
Primary sources
- United States Coast GuardAccessed 2026-08-30
- USCG Office of Commercial Vessel ComplianceAccessed 2026-08-30