Colour Blindness & Merchant Navy India: Which Jobs Are Still Possible?

Colour vision deficiency affects approximately 8% of men and 0.5% of women. If you’re one of them and dreaming of merchant navy — here’s exactly what’s closed, what’s open, and how to find out where you stand before investing in training.

Why Colour Vision Matters at Sea

Navigation at sea uses colour-coded signals extensively:

• Navigation lights: Red (port/left), Green (starboard/right), White (masthead/stern)
• Signal flags and lights
• Chart markings
• Safety signage and alarms

Deck officers must correctly identify these in all weather conditions at night. This is why colour vision requirements exist for navigation — it’s a genuine safety requirement, not bureaucracy.

What Is Tested: Ishihara vs. Lantern Test

Ishihara test (plates): The standard initial screening — coloured plates with numbers embedded. Pass/fail. Fails many people with mild deficiency.

Lantern test (Farnsworth): More specific — tests ability to distinguish red, green, and white lights at distance. You can fail Ishihara but pass the Lantern test.

DG Shipping medical for deck officers: If you fail Ishihara, the medical officer may administer the Lantern test. Passing Lantern may allow a “Colour Vision Deficient” notation on your certificate — which limits you to certain certificates.

What Is CLOSED for Colour-Deficient Candidates

Deck Officer route (all grades):

• DNS (Diploma in Nautical Science)
• B.Sc Nautical Science
• 3rd Officer, 2nd Officer, Chief Officer, Captain on watch-keeping vessels

The navigational watch responsibility requires full colour vision. No exceptions under current DG Shipping and STCW standards.

What Is OPEN — Your Real Options

Marine Engineering Officer — OPEN

Engine officers do not stand navigational watches. Colour vision requirements for engineering officers are significantly relaxed.

MEO Class 4, MEO Class 3, MEO Class 2, MEO Class 1 (Chief Engineer) — all accessible with colour deficiency, subject to the medical officer’s assessment.

This is the most common path for colour-deficient maritime aspirants. Many successful Chief Engineers have colour vision deficiency.

ETO (Electro-Technical Officer) — Generally Open

ETO work involves electrical and electronic systems — colour coding of wires is relevant, but this doesn’t require the same colour discrimination as navigation. Most ETOs with mild colour deficiency can qualify.

Verify with the medical officer at your DG Shipping exam.

GP Rating / Engine Rating — Generally Open

Ratings entry via GP Rating or directly as Oiler/Wiper — colour vision requirements are less strict. Most colour-deficient candidates can qualify for ratings roles.

Deck ratings (AB, Bosun) on watchkeeping vessels may have stricter requirements than engine ratings.

Shore-Based Maritime Careers — Fully Open

All shore-side maritime roles have no colour vision requirements:

• Maritime administration
• Freight/logistics management
• Ship chandling
• Marine insurance
• Port operations
• Cargo surveying

Testing Yourself First — Free Ishihara Online

Before spending on training or medical fees, do an Ishihara test online. Not a medical substitute, but it gives you a realistic picture.

Search: “Ishihara colour vision test online” — multiple free versions exist.

If you pass easily: Your chances of passing the medical colour vision test are good.

If you struggle: You likely have some deficiency — the engineering/ETO path is your best maritime route.

The Common Mistake

Too many people spend ₹8–15 lakh on DNS or Nautical Science courses, complete pre-sea training, and then discover at the medical (or worse, at MMD exam time) that colour vision rules out their planned certification.

Test first. Choose your path second. Medical check for colour vision costs almost nothing. DNS course costs lakhs.

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Not sure which maritime career path is open for you with colour deficiency? Ask SailorGPT — honest medical eligibility guidance.