The Hamilton Khaki Navy Frogman 41mm keeps the H-10 automatic movement, 80-hour power reserve and 30 bar (300m) water resistance of the cited 46mm model, while reducing the listed case diameter, thickness and lug width. The practical difference is a smaller set of dimensions—not a change to those core specifications. Whether it wears better on your wrist is personal.
What changes between the 41mm and 46mm Frogman?
For a like-for-like specification comparison, Hamilton’s black-dial, steel-bracelet 41mm reference is H77485130; the cited 46mm reference is H77815130. Their listed dimensions show that the 41mm is smaller not only across the case but also in thickness and lug width.
| Specification | Frogman 41, H77485130 | Frogman 46, H77815130 |
|---|---|---|
| Case diameter | 41mm | 46mm |
| Thickness | 13.09mm | 13.58mm |
| Lug width | 20mm | 22mm |
| Movement | Automatic H-10 | Automatic H-10 |
| Power reserve | 80 hours | 80 hours |
| Water resistance | 30 bar (300m) | 30 bar (300m) |
Hamilton lists these specifications on its 41mm product page and 46mm product page. The 41mm case is 5mm narrower in diameter, 0.49mm thinner and has a 2mm narrower lug width. Those measurements describe the references above; they do not establish how either watch will feel on a particular wrist.
What stays the same in function?
Hamilton identifies an automatic H-10 movement and an 80-hour power reserve for both sizes. Both cited references are listed with 30 bar (300m) water resistance. On those core specifications, the smaller Frogman does not give up the movement, reserve or rated water resistance shown for the larger reference.
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- AUTOMATIC MOVEMENT: Swiss H-10 movement with 80-hour reserve ensures consistent performance. Experience precision that matches both daily tasks and adventures, a testament to Swiss craftsmanship in automatic timekeeping.
- WATER RESISTANT TO 300M: Withstands 30 bar (300 meters), ideal for swimming and outdoor pursuits. Perfect for those who demand resilient accessories that accompany them confidently on their explorative journeys.
- MADE FOR THE DEEP: Designed with a 41mm stainless steel case and a striking black dial, this watch is water-resistant up to 300m, making it perfect for underwater exploration. Sapphire crystal ensures excellent visibility in any marine environment.
- PREMIUM MATERIALS: Rubber strap with pin buckle offers day-long comfort. The clean lines and sophisticated design make it the perfect accessory for both casual wear and formal attire, merging functionality with fashion.
- RICH HERITAGE: Over a century of Hamilton's legacy in field watches, admired for precision. Originally designed for WWI soldiers, these timepieces combine rugged durability with history, showcasing Hamilton's commitment to quality and innovation.
Hamilton’s Frogman 41 collection page also describes the 41mm model as retaining the range’s maritime design. Its features include a unidirectional bezel with raised numerals and indexes, a screw-down crown protected by a bridge-shaped crown guard, and Super-LumiNova accents on the dial. These are Hamilton’s descriptions of the watch, not a substitute for checking the specifications and instructions for a particular reference.
How the 41mm design differs visually
The size reduction is accompanied by design changes. In a review published May 18, 2023, Fergus Nash of Time+Tide observed softer, gear-shaped bezel edges, shorter lugs, more standard hour markers and a simpler crown guard on the 41mm version. Those are the reviewer’s visual observations rather than dimensions or claims published as specifications by Hamilton.
Rank #2
- AUTOMATIC MOVEMENT: Swiss H-10 movement with 80-hour reserve ensures consistent performance. Experience precision that matches both daily tasks and adventures, a testament to Swiss craftsmanship in automatic timekeeping.
- WATER RESISTANT TO 300M: Withstands 30 bar (300 meters), ideal for swimming and outdoor pursuits. Perfect for those who demand resilient accessories that accompany them confidently on their explorative journeys.
- MADE FOR THE DEEP: Designed with a 46mm stainless steel case and a striking black dial, this watch is water-resistant up to 300m, making it perfect for underwater exploration. Sapphire crystal ensures excellent visibility in any marine environment.
- PREMIUM MATERIALS: Rubber strap with pin buckle offers day-long comfort. The clean lines and sophisticated design make it the perfect accessory for both casual wear and formal attire, merging functionality with fashion.
- RICH HERITAGE: Over a century of Hamilton's legacy in field watches, admired for precision. Originally designed for WWI soldiers, these timepieces combine rugged durability with history, showcasing Hamilton's commitment to quality and innovation.
Hamilton characterizes the watch with the brand line, “Functional and wearable at once, this timepiece is a hero underwater and on land.” That is Hamilton’s marketing language; “wearable” is not an objective fit measurement.
Which size should you choose?
Choose based on how much wrist presence and fit you want, not on an assumption that one size is universally more comfortable. The 41mm reference has both shorter listed diameter and narrower lugs, while the difference in listed thickness is more modest. Wrist shape, strap or bracelet fit, and personal preference all affect how a watch wears.
Rank #3
- AUTOMATIC MOVEMENT: Swiss H-10 movement with 80-hour reserve ensures consistent performance. Experience precision that matches both daily tasks and adventures, a testament to Swiss craftsmanship in automatic timekeeping.
- WATER RESISTANT TO 300M: Withstands 30 bar (300 meters), ideal for swimming and outdoor pursuits. Perfect for those who demand resilient accessories that accompany them confidently on their explorative journeys.
- MADE FOR THE DEEP: Designed with a 46mm stainless steel case and a striking black dial, this watch is water-resistant up to 300m, making it perfect for underwater exploration. Sapphire crystal ensures excellent visibility in any marine environment.
- PREMIUM MATERIALS: Rubber strap with H-shaped buckle offers day-long comfort. The clean lines and sophisticated design make it the perfect accessory for both casual wear and formal attire, merging functionality with fashion.
- RICH HERITAGE: Over a century of Hamilton's legacy in field watches, admired for precision. Originally designed for WWI soldiers, these timepieces combine rugged durability with history, showcasing Hamilton's commitment to quality and innovation.
- Consider the 41mm if you prefer a smaller case and narrower lug width, or want the listed H77485130 configuration with a black dial and steel bracelet.
- Consider the 46mm if you prefer a larger case presence. Its cited reference keeps the same listed H-10 movement, 80-hour reserve and 30 bar (300m) water resistance.
- Check the exact configuration before deciding: Hamilton’s collection page describes black or khaki green dial options and bracelet or rubber-strap configurations, but not every combination should be assumed to share the same reference or availability.
Availability of the 41mm H77485130
Hamilton’s US page for H77485130 labels it “Past collection” and “Not available online,” while offering a retailer-finding path. That is the status shown on the US page, not proof that the watch is unavailable worldwide or cannot be found through a retailer or secondary-market seller. Check availability in your market and confirm the seller, reference and condition before buying.
Time+Tide’s review provides additional design context: The Hamilton Khaki Navy Frogman 41 is more compact but just as functional.
Quick Recap
Best Value
- AUTOMATIC MOVEMENT: Swiss H-10 movement with 80-hour reserve ensures consistent performance. Experience precision that matches both daily tasks and adventures, a testament to Swiss craftsmanship in automatic timekeeping.
- WATER RESISTANT TO 1000M: Withstands 100 bar (1000 meters), ideal for swimming and outdoor pursuits. Perfect for those who demand resilient accessories that accompany them confidently on their explorative journeys.
- MADE FOR THE DEEP: Designed with a 46mm titanium case and a striking black dial, this watch is water-resistant up to 1000m, making it perfect for underwater exploration. Sapphire crystal ensures excellent visibility in any marine environment.
- PREMIUM MATERIALS: Rubber strap with pin buckle offers day-long comfort. The clean lines and sophisticated design make it the perfect accessory for both casual wear and formal attire, merging functionality with fashion.
- RICH HERITAGE: Over a century of Hamilton's legacy in field watches, admired for precision. Originally designed for WWI soldiers, these timepieces combine rugged durability with history, showcasing Hamilton's commitment to quality and innovation.
Rank #4
- AUTOMATIC MOVEMENT: Swiss H-10 movement with 80-hour reserve ensures consistent performance. Experience precision that matches both daily tasks and adventures, a testament to Swiss craftsmanship in automatic timekeeping.
- WATER RESISTANT TO 300M: Withstands 30 bar (300 meters), ideal for swimming and outdoor pursuits. Perfect for those who demand resilient accessories that accompany them confidently on their explorative journeys.
- MADE FOR THE DEEP: Designed with a 41mm stainless steel case and a striking black dial, this watch is water-resistant up to 300m, making it perfect for underwater exploration. Sapphire crystal ensures excellent visibility in any marine environment.
- PREMIUM MATERIALS: Stainless steel bracelet with folding clasp offers day-long comfort. The clean lines and sophisticated design make it the perfect accessory for both casual wear and formal attire, merging functionality with fashion.
- RICH HERITAGE: Over a century of Hamilton's legacy in field watches, admired for precision. Originally designed for WWI soldiers, these timepieces combine rugged durability with history, showcasing Hamilton's commitment to quality and innovation.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
