Strap for SUB 300 Carbon Aqua Lung US Divers

The lug width of the Doxa SUB 300 822.70.101AQL.20 is 20mm. This measurement represents the internal distance between the lugs (strap mounting points) on the watch case. To verify this with precision, use a digital calliper and measure the space between the lug holes: the value must be exactly 20.00mm. Always measure internally; external measurement is unreliable for strap compatibility.

Selection depends on intended use. For frequent diving, we recommend FKM (Viton) rubber: waterproof, resistant to saltwater corrosion, and excellent grip underwater. For daily formal wear, vegetable-tanned alligator leather offers structured elegance and develops rich patina over time. NATO straps in cotton or nylon are ideal for combining durability with practicality: they resist saltwater absorption and pull on easily even whilst wearing a wetsuit. All our 20mm straps are compatible with this model's lugs.

Position the watch on a soft support to avoid scratches on the carbon and titanium case. Locate the lug pins (stainless steel springbars that pass horizontally through the case). Using a springbar removal tool, press downward on one side of the pin whilst gently extracting it outward. Repeat for the opposite lug. Remove the old strap. Insert the new strap, aligning its holes with the pins, then press the pin firmly back into position until you feel a click. Verify that the strap is securely attached before wearing the watch.

Yes, any strap manufactured for 20mm lug width is compatible with your Doxa SUB 300, provided the pin holes are positioned correctly at standard 20mm centre-to-centre spacing. Milano Straps' artisanal straps are custom-made to this specification and guarantee perfect fit to the lugs. Avoid generic straps claiming 'approximate' compatibility; tolerance must be below 0.5mm for secure attachment.

Leather strap longevity depends on moisture and saltwater exposure. If worn for frequent diving, durability diminishes to 18–24 months before the leather begins deteriorating, even with superior vegetable tanning. In daily indoor, dry-use contexts, premium shell cordovan or alligator will last 3–4 years or longer. For regular diving, rotate between a leather strap (formal use) and an FKM rubber strap (diving use) to extend both lifespans. Rinsing in fresh water after immersion and complete drying significantly protects leather.