Strap for Seamaster Aqua Terra 150M Co-Axial 38.5 Red Gold / Diamond / Black

The lug width of this model is exactly 18mm. This distance represents the space between the inner shoulders of the case and is specific to reference 231.58.39.21.51.001. It is not interchangeable with different sizes (such as 20mm or 16mm): a strap with incorrect lug width will create visible gaps and unwanted lateral movement. To verify it, measure with a caliper the internal distance between the two attachment points on the case.

For the 231.58.39.21.51.001, alligator remains the most coherent choice: the regular grain and pronounced scales enhance the nautical-elegant character of the watch. Dark brown or black alligator creates elegant contrast with rose gold. Shell cordovan represents an excellent alternative for those who appreciate leathers that evolve over time, developing natural patina and darkening. Vegetable-tanned calf is more versatile and modern, ideal for those seeking flexibility in use.

The Omega Aqua Terra strap is changed via the spring bars that connect the lugs to the case. Use a spring bar tool to lift the pin and remove the old strap. Repeat the operation on the other lug. Insert the pins in the correct position on the new strap and press until they click into place. If you lack experience, consult a professional watchmaker to avoid scratching the case.

Yes, the 231.58.39.21.51.001 is fully compatible with quality aftermarket straps, provided they respect the 18mm lug width. Avoid generic or poor-quality straps: since the case is in 18kt rose gold (a noble material), the strap must meet the same construction and aesthetic standards. Customizable artisanal straps with vegetable tanning or rare leathers guarantee durability and a patina that elegantly evolves over time.

The lifespan of a leather strap depends on frequency of use, moisture exposure, and tanning quality. A quality artisanal alligator or cordovan strap, with vegetable-tanned leather and hand stitching, lasts an average of 3-5 years with daily use, potentially extending to 5-7 years with proper maintenance (regular drying, avoiding prolonged contact with salt water). A shell cordovan strap tends to last longer thanks to the natural density of horse leather. The 18-month warranty on custom straps (such as those created by Casati Milano) covers construction defects and irregular stitching.