Glossary of maritime terminology
- S&T Heat Exchanger
- Salvage
- Sanitary System
- SAR
- Satellite Communications System
- Satellite Speed Log
- SCBA
- SCR
- Sea Mark
- Sea Time
- Sea Trial
- Seafarer
- Seafarer App
- Seafarer Job
- Seafarer Resume
- Seafarer Training Provider
- Seaman's Book
- Seamark
- Search and Rescue
- Seaspeak
- Seaworthiness
- Seaworthiness Certificate
- Second Dog Watch
- Second Engineer
- Secondary Clock
- Seismic Survey Vessel
- Selective Catalytic Reduction System
- Self-Contained Breathing Apparatus
- Self-Driving Ship
- Self-Geared Vessel
- Self-Trimming Ship
- Self-Unloading Vessel
- Semi Submersible Rig
- Semi Submersible Vessel
- Sewage Treatment Plant
- Sheddage
- Shell and Tube Heat Exchanger
- Shifting
- Ship Log
- Ship Toilet
- Ship's Articles
- Ship's Carpenter
- Ship's Cook
- Ship's Electrician
- Ship's Plumber
- Shipbroker
- Shipfitter
- Shipping Agent
- Shipping Alliance
- Shore Leave
- Shuttle Tanker
- Side Thruster
- Sierra
- Signal Lamp
- Signal Light
- Single Point Anchor Reservoir Platform
- Sister Ship
- Slave Clock
- Slop Chest
- Smart Port
- SMCP
- SOLAS
- Sonar
- SPAR
- Speed Log
- Spreader
- Standard Marine Communication Phrases
- Starboard
- STCW
- Steamship
- Steering Gear
- Stern
- Stern Thruster
- Stern Tube
- Sternway
- Stevedore
- Steward
- Stewardess
- Stewards Department
- Stowage
- Stowaway
- Straddle Carrier
- Stranding
- Stripping
- Stuffing
- Suezmax
- Suezmax Tanker
- Superyacht
- Supramax Bulk Carrier
- Supramax Vessel
- Survival Craft
- Survival Suit