Seiko Prospex 62MAS SPB143 Review: The Perfect Blend of Vintage and Modern

Introduction

Seiko has built a reputation as a leader in the dive watch world, producing some of the most reliable and value-packed timepieces. Among them, the Seiko Prospex SPB143 stands out as a modern reinterpretation of the legendary 1965 Seiko 62MAS—Japan’s first-ever dive watch.

But this isn’t just a homage piece—the SPB143 is packed with modern innovations that make it a serious dive watch contender while maintaining a vintage-inspired aesthetic.

This in-depth review covers:
✅ The design and build quality
✅ The movement and accuracy
✅ Strap options and wearability
✅ How it compares to other Seiko divers
✅ Who this watch is perfect for

Let’s take a deep dive into everything the SPB143 has to offer! ⌚🌊

---

1. The Legacy of the Seiko 62MAS 🏆

Before we discuss the SPB143, it's important to understand its heritage.

• In 1965, Seiko introduced the 62MAS, its first professional dive watch.
• It featured 150m of water resistance, a simple case design, and a legible dial—everything a diver needed.
• Over the years, the 62MAS became a grail watch for collectors, inspiring modern reissues.

The Seiko Prospex SPB143 is not an exact reissue but a modernized interpretation, making it more wearable, refined, and functional while maintaining the spirit of the original.

---

2. Design & Build Quality: A Classic Reinvented 🔥

A. Case & Dimensions

The SPB143 finds the perfect balance between vintage charm and modern usability with its 40.5mm stainless steel case.

• Size: 40.5mm (diameter) x 13.2mm (thickness) x 47.6mm (lug-to-lug)
• Material: Stainless steel with Seiko’s super-hard coating (scratch-resistant)
• Bezel: 120-click unidirectional bezel with aluminum insert
• Crown: Screw-down crown for enhanced water resistance

💡 Why It Works: The dimensions make it wear smaller than a typical dive watch, making it ideal for everyday wear. The brushed finishing and polished chamfers give it a high-end look.

B. Dial & Hands

The dial of the SPB143 is where vintage meets modern perfection:

• Color: Dark gray sunburst dial (shifts from black to silver in different lighting)
• Markers & Hands: Rectangular, filled with Lumibrite for high visibility
• Crystal: Domed sapphire crystal with AR (anti-reflective) coating

💡 Why It Works: The simple yet elegant dial is ultra-legible, perfect for divers and everyday wearers alike.

---

3. Movement & Performance: The Seiko 6R35 ⚙️

Inside the SPB143 is Seiko’s 6R35 automatic movement, a step above their entry-level calibers.

A. Specs & Features

• Automatic & Hand-Winding
• Power Reserve: 70 hours 🔋 (nearly 3 days!)
• Beats Per Hour: 21,600 vph
• Jewels: 24
• Hacking: Yes ✅

B. Accuracy

Seiko officially rates the 6R35 at +25/-15 seconds per day. However, real-world accuracy varies:

✅ Some users report -5 to +10 seconds/day (very good for a mid-range movement!)
❌ Others experience inconsistent timekeeping (typical for non-COSC-certified watches).

💡 Verdict: The 6R35 is reliable but not the most accurate. It’s perfect for everyday wear but may need regulation for better precision.

---

4. Water Resistance & Diving Capability 🌊

The SPB143 is rated for 200m (20 bar) water resistance, making it a true dive watch.

A. Diving Features

✔️ Screw-down crown for better water resistance
✔️ 120-click bezel with precise markings for dive timing
✔️ Lume brightness is excellent—easy to read underwater

💡 Verdict: While it isn’t ISO-certified, the SPB143 can handle recreational diving with ease.

---

5. Bracelet & Strap Options: The Strap Monster 🏆

The SPB143 is one of Seiko’s most versatile watches—it looks incredible on multiple strap types.

A. Stock Bracelet

• Material: Stainless steel, three-link design
• Clasp: Secure folding clasp with micro-adjustments
• Verdict: Comfortable but not the best—many users prefer aftermarket options.

B. Best Aftermarket Straps

• Rubber/Silicone – Great for diving and comfort
• NATO Straps – Military-inspired, casual, and breathable
• Leather – Classy and perfect for dressier occasions

💡 Verdict: The SPB143 is a strap monster! Easily switch between bracelet, NATO, rubber, or leather to fit any style.

---

6. How Does It Compare to Other Seiko Divers? 🤔

Model	SPB143	Seiko SKX007	Seiko MM200 (SBDC061)
Case Size	40.5mm	42mm	44mm
Movement	6R35	7S26 (Non-hacking)	6R15 (Older Gen)
Power Reserve	70 hours	40 hours	50 hours
Water Resist.	200m	200m (ISO-certified)	200m (ISO)
Bezel Action	Smooth	Stiff	Very smooth
Lume	Excellent	Excellent	Excellent
Price	$$$	$$	$$$$

💡 Verdict:

• The SPB143 offers premium upgrades over the SKX007 (better movement, case finish, and sapphire crystal).
• It’s smaller and more wearable than the Marine Master 200.
• Overall, it’s one of the best value mid-range Seiko divers available!

---

7. Who Should Buy the Seiko SPB143? 🎯

The SPB143 is perfect for:
✔️ Seiko collectors looking for a modern 62MAS alternative
✔️ Everyday wearers who want a rugged yet classy dive watch
✔️ Strap lovers who want a “strap monster” for different looks
✔️ Mid-range luxury buyers looking for something better than an SKX but below a Marine Master

❌ Who it’s NOT for:

• Those wanting a cheaper alternative (check the Seiko SKX or Turtle series).
• Those wanting ultimate accuracy (a Swiss ETA movement would be better).

---

Final Verdict: Is the SPB143 Worth It? ✅

✅ Pros:
✔️ Vintage-inspired design with modern upgrades
✔️ Perfectly sized at 40.5mm for all wrists
✔️ Durable & versatile—great for daily wear or diving
✔️ Strap monster—looks good on anything!

❌ Cons:

• Accuracy can vary
• Bracelet could be better

💡 Final Rating: 9/10 🔥🔥🔥

---

Where to Buy 🛒

📍 Official Seiko Retailers
📍 Trusted online dealers