Seiko has built a solid reputation for producing high-quality dive watches that rival even the most expensive Swiss brands. Among its many iconic designs, the Seiko Military Submariner (MilSub) models have gained cult status among collectors and enthusiasts. These watches, inspired by military aesthetics and built for rugged performance, have become valuable timepieces over the years. If you’re looking to invest in a vintage Seiko MilSub, this guide highlights the best models that offer historical significance, reliability, and potential appreciation in value.

What is a Seiko MilSub?

The term “MilSub” originally referred to military-issued Submariner watches, particularly those made by Rolex for the British Ministry of Defence (MOD). However, Seiko has also created military-style dive watches that share similar DNA with these historic timepieces. These models are not official military-issue but embody the spirit of tough, no-nonsense tool watches, making them highly desirable among collectors.

Why Invest in a Vintage Seiko MilSub?

Seiko MilSub watches have consistently increased in value due to their heritage, durability, and limited availability. Here’s why they are worth investing in:

• Affordability Compared to Swiss MilSubs – Vintage Seiko MilSubs are far more accessible than Rolex or Omega military dive watches.

• Durability – Seiko’s legendary build quality ensures these watches remain functional for decades.

• Growing Collectibility – As interest in vintage Seikos rises, certain models are becoming more sought after.

• Unique Design – Seiko MilSubs often feature distinctive case designs, bezel layouts, and military-inspired dial aesthetics.

Now, let’s dive into the best vintage Seiko MilSub models worth investing in.

1. Seiko 6105-8110/8119 “Captain Willard” (1968-1977)

Why It’s a Great Investment

The Seiko 6105-8110/8119, nicknamed the “Captain Willard,” is one of the most famous vintage Seiko dive watches. It gained legendary status after being worn by Martin Sheen in the 1979 film Apocalypse Now.

Key Features:

• 42mm asymmetric cushion case for extra crown protection

• Hardlex crystal for durability

• 150m water resistance

• Caliber 6105B automatic movement with hacking seconds

Current Market Value:

• Expect to pay $2,500-$5,000, depending on condition and originality.

This watch’s pop culture significance, military association, and robust build make it a top-tier investment piece.

2. Seiko 6306-7001 & 6309-7040/7049 “Turtle” (1976-1988)

Why It’s a Great Investment

The Seiko 6306 and 6309 Turtle series are some of the most recognizable Seiko dive watches. Their robust design and reliability made them favorites among professional divers and military personnel.

Key Features:

• Cushion-shaped 45mm case with integrated crown guards

• Caliber 6306 (Japan-only, 21 jewels, hacking) & 6309 (non-hacking, 17 jewels)

• 200m water resistance

• Highly legible dial and bezel design

Current Market Value:

• $800-$2,500 depending on condition and movement type

The 6306-7001 (with a hacking movement) is rarer and more valuable than the 6309 models, making it a prime investment choice.

3. Seiko 7548-7000 Quartz Diver (1978-1985)

Why It’s a Great Investment

Seiko’s first quartz-powered dive watch, the 7548-7000, was a groundbreaking release. Despite being a quartz model, it retained the ruggedness and reliability of mechanical MilSubs.

Key Features:

• Same case design as the 6309 “Turtle” but slimmer

• Caliber 7548 quartz movement – highly accurate and long-lasting

• 200m water resistance

• Day-date complication

Current Market Value:

• $600-$1,500, with original dials and bezels fetching a premium

Collectors are increasingly appreciating vintage Seiko quartz models, making this an undervalued investment with high potential.

4. Seiko 7C43-7000/700A “The Forgotten MilSub” (1985-1990s)

Why It’s a Great Investment

The 7C43-7000 is often called “The Forgotten MilSub” because it was designed for military and professional use but remains under the radar compared to other Seiko divers.

Key Features:

• Stainless steel 42mm case with screw-down crown

• Caliber 7C43 quartz movement (highly accurate & robust)

• 300m water resistance – outperforming many Swiss MilSubs!

• No-nonsense military aesthetic

Current Market Value:

• $800-$2,000, depending on condition

This watch is an excellent sleeper investment, as more collectors recognize its historical and functional significance.

5. Seiko 7002-7000/7009 “Pre-SKX” (1988-1996)

Why It’s a Great Investment

The Seiko 7002 series served as the bridge between the 6309 Turtle and the famous SKX007, making it a historically important model.

Key Features:

• 41mm stainless steel case

• Caliber 7002 automatic movement (non-hacking, non-hand-winding)

• 200m water resistance

• Uni-directional dive bezel

Current Market Value:

• $400-$1,200 depending on originality

As SKX prices continue to rise, 7002 models are the next in line for appreciation, making them a smart investment today.

Final Thoughts: Which Vintage Seiko MilSub Should You Buy?

For serious investors, the Seiko 6105-8110 “Captain Willard” is the best high-value investment due to its historical importance and rising demand.

For mid-range collectors, the 6306-7001 or 7C43-7000 offer great collectibility with room for appreciation.

For budget-conscious investors, the 7548-7000 and 7002-7000 present undervalued opportunities with solid growth potential.

Pro Tip: How to Buy Vintage Seiko MilSubs Wisely

• Check authenticity – Avoid frankenwatches (mismatched parts).

• Look for original dials, hands, and bezels – Replacements lower value.

• Buy from reputable sellers – Trusted vintage watch dealers or forums like Watchuseek and eBay.

• Consider servicing costs – Mechanical models may need restoration.

Investing in vintage Seiko MilSubs is a rewarding venture that combines historical appreciation with the thrill of collecting. As demand grows, these timepieces will continue to rise in value, making them a smart choice for both seasoned collectors and new investors. Start your collection today and secure a piece of Seiko’s legendary dive watch heritage!