Price
CaptainsGround
Free to start · Pass plans from $79
SeaSources
Free (downloadable modules also offered)
TL;DR
SeaSources: free, huge legacy question pool covering AB, QMED, deck and engine, online since 1996. CaptainsGround: free to start, original questions calibrated to the current NMC exam format, every answer cited to 33/46 CFR, COLREGs, or a public engineering reference — plus flashcards and a mock exam.
Side by side
Credential coverage
CaptainsGround
OUPV / Master + AB and QMED (Oiler, Junior Engineer, Electrician/Refrigerating)
See QMED tracksSeaSources
Broad — AB, QMED, and licensed deck & engine
Question source
CaptainsGround
Original questions, calibrated to the current NMC format
SeaSources
Large pool rooted in the USCG bank published through 2015
Citations on every answer
CaptainsGround
Yes — linked to the rule it tests
SeaSources
Answer keys; limited sourcing
Currency of the bank
CaptainsGround
Built to the current exam format; no leaked questions
SeaSources
Site states it tracks the CG databank; the official bank has not been public since 2016
Study tooling
CaptainsGround
Lessons + drills + FSRS flashcards + NMC-format mock
SeaSources
Practice quizzes and final-exam pools
Interface
CaptainsGround
Modern, mobile-friendly web app
SeaSources
Long-standing, utilitarian
Which should you pick?
Pick CaptainsGround if…
- Price: Free to start · Pass plans from $79
- Credential coverage: OUPV / Master + AB and QMED (Oiler, Junior Engineer, Electrician/Refrigerating)
- Question source: Original questions, calibrated to the current NMC format
- Citations on every answer: Yes — linked to the rule it tests
- Currency of the bank: Built to the current exam format; no leaked questions
- Study tooling: Lessons + drills + FSRS flashcards + NMC-format mock
- Interface: Modern, mobile-friendly web app
Pick SeaSources if…
- Price: Free (downloadable modules also offered)
- Credential coverage: Broad — AB, QMED, and licensed deck & engine
- Question source: Large pool rooted in the USCG bank published through 2015
- Citations on every answer: Answer keys; limited sourcing
- Currency of the bank: Site states it tracks the CG databank; the official bank has not been public since 2016
- Study tooling: Practice quizzes and final-exam pools
- Interface: Long-standing, utilitarian
Bottom line
SeaSources is a genuinely useful free resource with decades of breadth, and many mariners have passed with it. The catch for everyone is that the Coast Guard stopped publishing its question bank in 2016, so no free pool can mirror the live exam. CaptainsGround's answer is original questions built to the current format with a citation on every one — use SeaSources for raw volume, CaptainsGround when you want to verify the rule behind each answer.
Last verified:
Primary sources
- SeaSources.net — free USCG deck & engine exam prep (established 1996) (retrieved 2026-07-16)
- SeaSources.net — QMED question modules (retrieved 2026-07-16)
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