2026-05-18
Best Watch Straps for the Casio W800H
Best Watch Straps for the Casio W800H
The Casio W800H is one of the most capable watches ever sold for under £30. The specification is absurd for the price: 100m water resistance, 10-year battery life, LED backlight, dual time, full calendar, stopwatch, and alarm — all in a 36.8mm resin case that weighs almost nothing and will survive conditions that would destroy watches costing fifty times as much. The W800H is not trying to look like anything other than what it is. The black resin case, the square digital dial, and the functional black resin strap are all honest expressions of a watch designed to work rather than impress.
It is also one of the most popular watches for strap upgrades in the Casio community — not because the original strap is inadequate, but because the W800H's combination of 100m water resistance and robust character makes it genuinely useful across a wide range of active contexts where a quality alternative strap is more appropriate than the original resin.
There is one important technical constraint to understand before ordering a strap for the W800H, and it matters more for this watch than for almost any other.
Casio W800H Strap Size — And the Lug Clearance Warning
The Casio W800H uses 18mm lugs — confirmed by Casio's own OEM strap code (738-EA2-18) which explicitly states 18mm. 36.8mm case diameter, 44.2mm lug-to-lug. Standard spring bars.
Critical fitting note: The W800H has very limited clearance between the spring bars and the case. The spring bars sit unusually close to the case walls. This means thick padded leather straps and bulky two-piece straps may not seat correctly or may be very difficult to install without straining the resin lugs. Single-pass nylon, elastic straps, flat leather, and perlon all fit correctly. Moderately padded leather at 3mm or under should seat with care.
W800H-1AV (black dial, black case) — 18mm W800H-1BVES (black dial, white case) — 18mm W800HG-9AV (gold-tone case) — 18mm
The 18mm lug width is shared with the Casio F91W, A168, and A158 — the same CNS 18mm strap fits all four.
Best Single-Pass Nylon for the Casio W800H
Single-pass nylon is the most appropriate and most practical strap for the W800H. The thin single-layer construction threads through the tight lug clearance without difficulty, and the W800H's 100m water resistance makes it genuinely suited to active and water use where nylon is the most practical material.
Single-pass nylon — Original at 18mm with the CNS solid buckle — the most recommended W800H upgrade. The single-pass construction threads through the tight lug clearance correctly where some two-piece straps struggle. Most appropriate W800H colourways:
- Black — the most operationally coherent with the W800H's all-black character. A W800H on black single-pass nylon is the most purposeful budget diver combination available.
- Olive / khaki — for a military-field character. The W800H's rugged brief suits olive nylon directly.
- Admiralty Grey — for the most composed operational combination.
- Black and grey — the most understated collector combination.
Marine Nationale elastic at 18mm — the most comfortable W800H daily wear option. The elastic construction also eliminates the tight lug clearance issue entirely — the elastic threads through without any spring bar fitting difficulty. The W800H's 100m water resistance makes the Marine Nationale's active diving heritage entirely appropriate.
Paratrooper elastic at 18mm — the most comfortable daily option and the easiest to fit given the tight lug clearance.
RAF single-pass nylon at 18mm — for the most specifically British military heritage combination.
Best Rubber Straps for the Casio W800H
The W800H's 100m water resistance makes FKM rubber the most appropriate material for serious water use. Casio ships the W800H on resin — FKM is the direct upgrade for active diving, swimming, and water sports.
Classic FKM rubber in black at 18mm — the most practical active choice. Black FKM on the W800H's black resin case creates a unified operational combination. Note the lug clearance — choose a strap with thin end pieces rather than thick moulded ends.
Tropical style FKM in black at 18mm — for a more characterful rubber combination. The vintage basket-weave texture gives the budget diver an unexpected visual character.
Best Leather and Perlon for the Casio W800H
Leather on the W800H creates the most surprising transformation in this guide — the rugged budget diver becomes a casual everyday watch. Given the tight lug clearance, flat leather only.
Classic flat calfskin in black at 18mm — the most formally correct W800H combination. Flat construction is essential for the tight lug clearance — no padded leather.
Brown vintage two-stitch calfskin at 18mm — for the most characterful combination. The warm brown against the black digital case creates a warm-cool contrast that references the ironic collector combination made famous by the F91W on brown leather. Flat construction — the two-stitch strap's flat profile seats correctly in the tight clearance.
Dark brown flat calfskin at 18mm — the most versatile everyday leather.
Grey perlon at 18mm — the most refined casual option. Perlon's slim 1.5-2mm construction fits the tight lug clearance without any difficulty.
Black perlon at 18mm — the most minimal fabric choice.
The Casio Budget Cluster
CNS covers the complete Casio budget range:
Casio F91W — 18mm. The original. Drilled lugs, open clearance.
Casio A168 and A158 — 18mm. The stainless Illuminator family.
Casio W800H — 18mm. The 100m budget diver. Tight lug clearance — single-pass and flat straps only.
Recommended Combinations
Most operationally correct — black single-pass nylon at 18mm — the budget diver on a budget military strap.
Most comfortable active — Marine Nationale elastic at 18mm — eliminates the lug clearance issue, suits the W800H's water resistance.
Most operational rubber — black FKM rubber at 18mm for swimming and diving.
Most characterful — brown vintage two-stitch flat calfskin at 18mm — the ironic collector combination.
Most refined casual — grey perlon at 18mm.
Military field character — olive single-pass nylon at 18mm.
Frequently Asked Questions
What size strap does the Casio W800H take? 18mm — confirmed by Casio's own OEM strap code (738-EA2-18). The W800H shares its 18mm lug width with the Casio F91W, A168, and A158.
Why won't thick straps fit the Casio W800H? The W800H has very limited clearance between the spring bars and the case walls. Thick padded straps and bulky two-piece constructions cannot seat correctly in this tight space without straining the resin lugs. Single-pass nylon, elastic straps, flat leather, and perlon all fit correctly within the clearance. This is the single most important thing to know about fitting aftermarket straps to the W800H.
What is the best strap for the Casio W800H? Black single-pass nylon at 18mm — the most operationally coherent combination for a 100m water-resistant budget diver. Marine Nationale elastic for the most comfortable option that also eliminates the lug clearance fitting issue.
Does the W800H take the same strap as the F91W? Yes — both use 18mm lugs. However the W800H has significantly tighter lug clearance than the F91W, which has open drilled lugs. A strap that fits the F91W easily may not seat correctly on the W800H. Always choose flat, thin constructions for the W800H.
All CNS straps for the Casio W800H are available at 18mm. Standard delivery worldwide. 30-day returns.