Which is cheaper, the Marathon Steel Navigator SSNAV-D Auto or the Formex Reef 42 mm?

At MSRP the Marathon Steel Navigator SSNAV-D Auto is the cheaper of the two at $1,400, against $2,414 for the Formex Reef 42 mm — a $1,014 gap before any retailer discounting.

Which is bigger, the Marathon Steel Navigator SSNAV-D Auto or the Formex Reef 42 mm?

The Formex Reef 42 mm wears larger at 42mm versus 41mm for the Marathon Steel Navigator SSNAV-D Auto — a 1mm difference across the dial.

Which has better water resistance, the Marathon Steel Navigator SSNAV-D Auto or the Formex Reef 42 mm?

The Formex Reef 42 mm is rated to 300m versus 60m for the Marathon Steel Navigator SSNAV-D Auto.

Which has a longer power reserve, the Marathon Steel Navigator SSNAV-D Auto or the Formex Reef 42 mm?

The Formex Reef 42 mm carries a 56-hour power reserve against 40 hours on the Marathon Steel Navigator SSNAV-D Auto.

What movement does the Marathon Steel Navigator SSNAV-D Auto run compared to the Formex Reef 42 mm?

Both watches run automatic movements — the Marathon Steel Navigator SSNAV-D Auto uses the Sellita SW220-1 and the Formex Reef 42 mm uses the Sellita SW300-1.

Side by side

Marathon Steel Navigator SSNAV-D AutovsFormex Reef 42 mm

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

Marathon Steel Navigator SSNAV-D Auto

41mm-steel-navigator-automatic-w-date-ssnav-d-on-ballistic-nylon

MSRP $1,400

Formex Reef 42 mm

reef-42mm-automatic-cosc-300m-black

MSRP $2,414

At a glance

11 of 29 specs differ

Diameter

Steel Navigator SSNAV-D Auto41mm

Reef 42 mm42mm

Power Reserve

Steel Navigator SSNAV-D Auto40h

Reef 42 mm56h

Water Resistance

Steel Navigator SSNAV-D Auto60m

Reef 42 mm300m

MSRP

Steel Navigator SSNAV-D Auto$1,400

Reef 42 mm$2,414

Full specifications

Case

7 specs

Crystal & Dial

1 specs

Lume

None

Super-LumiNova

Movement

2 specs

Caliber

Sellita SW220-1

Sellita SW300-1

Power Reserve

40h

56h

Pricing

1 specs

MSRP

$1,400

$2,414

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What people say

Owners + reviewers, side by side

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Marathon Steel Navigator SSNAV-D Auto

The Marathon Steel Navigator SSNAV-D Auto is praised for its durable construction, featuring a sandblasted steel case with improved lugs, a bi-directional bezel with excellent action, and 100m water resistance. Owners appreciate the constant visibility provided by self-illuminating tritium gas tubes and the precision of its ETA F06.412 quartz movement, which offers accuracy to about 10 seconds per year. The watch includes a GMT bezel for dual timekeeping and a synthetic sapphire crystal. Overall, owners and reviewers rate the Marathon Steel Navigator SSNAV-D Auto highly for its robust tool-watch design and reliable tritium illumination.

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Formex Reef 42 mm

The Formex Reef 42 mm is widely praised for its comfortable bracelet featuring a micro-adjust clasp, COSC-certified Sellita movement, and excellent build quality. Owners appreciate the gradient dial's visual appeal and the overall wearability. Some owners note the seconds hand does not perfectly align with markers, and one owner found the lugs' taper hinders third-party strap fit. The bracelet's length and sporty design are noted as limiting versatility by some. On balance, owners and reviewers rate the Formex Reef 42 mm highly for its impressive wearability and value at the price point.

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