Omega · Aqua Terra
Strap for Omega Aqua Terra 231.15.39.21.51.001
The Seamaster Aqua Terra 150M Co-Axial 38.5 Stainless Steel / Diamond / Black / Bracelet takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
Recommended spring bar
Straps for the Aqua Terra 231.15.39.21.51.001
Selected for the 20 mm lug width · workshop selection
Black Alligator Strap with Light Blue Edges€149
Red Alligator Strap Water Resistant€195
Green Rubberized Alligator Strap with Ecru Tribal Stitching€149
Hammered Calfskin Strap Light Blue€98
Vintage Olive Green Calf Leather Watch Strap★ 4.5 · 4€80
What I'm asked about the Omega Aqua Terra 231.15.39.21.51.001
What strap size does the Omega Aqua Terra 231.15.39.21.51.001 take?
The Omega Aqua Terra 231.15.39.21.51.001 needs 20 mm between the lugs, usually 16 mm at the buckle. It's the size I've been fitting on it for years.
Can the strap on the Omega Aqua Terra 231.15.39.21.51.001 be changed?
Yes. It has spring bars between the lugs: with the right tool the strap comes off in a minute. If you'd rather not risk a scratch, I do it in the workshop.
Can I put a leather strap on the Omega Aqua Terra 231.15.39.21.51.001?
Yes, in 20 mm leather. On a 39 mm case a calf strap works every day; if you want something more, alligator.
Which strap do you recommend for the Omega Aqua Terra 231.15.39.21.51.001?
A 20 mm calf strap, for every day. You'll find it ready in the 20 mm collection. If you'd rather have something built on your wrist, the Casati atelier.
The Aqua Terra 231.15.39.21.51.001, seen from the bench
Frequently asked questions
What is the best strap material for this model?
Black or dark brown alligator is the optimal choice, as it reflects the minimalist aesthetic code of the Aqua Terra. Shell cordovan represents a premium alternative for durability and ageing patina. Calf leather tinted in cognac or mid-brown tones creates a refined yet less formal pairing. Avoid rubber and canvas, which are too casual for the identity of this model.
What aftermarket strap can I use for the 231.15.39.21.51.001?
Any strap constructed with a 20 millimetre lug width is compatible, provided the construction respects Omega tolerances (±0.2mm). Avoid generic straps that claim approximate compatibility. Bespoke artisanal straps guarantee perfect fit without vertical play and allow you to choose leather, colour, and stitching thread according to your aesthetic preferences.
How long does a leather strap last on an Omega Aqua Terra watch?
Durability varies based on material, usage, and maintenance. Alligator and shell cordovan maintain structural integrity for 5–8 years of daily wear. Vegetable-tanned calf typically lasts 3–4 years. Exposure to sweat, moisture, and extreme temperatures accelerates wear. A well-maintained strap (dried after water exposure, stored in a temperature-controlled environment) ages with elegant patina. The 18-month warranty from Casati Milano covers manufacturing defects.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only
The atelier's website: casatimilano.com