# Fortis b-42 Marine Master



## GeorgeRado (Nov 4, 2008)

Hey Guy's,
Just bought a new Marine Master and I've just found out it's a push/pull crown. Just assumed it would be a screw crown.
I've only had one other sports/diver with a push pull crown and it had a very annoying tendancy to puul out and change the time on me while I was wearing it.
I haven't seen any complaints regarding this with the Fortis but I thought I'd ask some owners how it's working for them.
Is it easily pulled out? has it ever pulled out accidently?
Any info would be greatly appreciated.
George


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## cnmark (Jul 30, 2006)

As this is sort of a FAQ, may be a little more about Fortis B-42 and crowns:

When the series was introduced, all B-42 had screw down crowns. However, there have been issues with the screw down crowns in the second series (case back umbers: AAA.BB.CCC.*2*), because the screw down crown design was changed to inner threads (much finer) - many users managed to shear off these fine threads.

Since early 2006 Fortis started changing the screw down crowns in the new production models to push pull crowns (new series of case back numbers: AAA.BB.CCC.*3*), the (production) transition was finished around autumn 2006. Unfortunately older production models are still in stock at ADs everywhere, and many people including dealers do not even know that there has been a change.

In case the screw down crown on an older B-42 has problems, Fortis does the repair on warranty (even if expired), the new push pull crown system will be installed. Fortis did also recall all watches from the second series that still were at the national distributors (only those, not the watches already delivered to ADs) and had them factory-modified. Due to this recall one can now find watches with AAA.BB.CCC.2 case back numbers and with the new crown at the dealers.

The first watch that came _*only with the push pull crown*_ was the Marinemaster (ref. number 647.10.41 / case back number 647.10.158.3) - introduced to the market in summer 2006.

Water resistance (20 bar or 200 m) is not affected by this crown. Back in October 2006 the German watches magazine "Uhrenmagazin" did a test on divers watches, including the B-42 Marinemaster (an English translated version of the this test was published in "WatchTime", sometime in 2008). The test was done according to the ISO 6425 diver watch standards, these require for the water resistance test the watch submerged in water at 125% of the rated pressure, duration 60 minutes - 25 bar (250 m) in case of the Fortis. The watch must continue running without noticeable rate change, not water intrusion is allowed.

This test has been hotly discussed, because initially a Breitling SO Steelfish XL (imploded crystal) and a Doxa Sub 750T Pro (stopped running) failed during the pressure tests (additional tested samples held). Nobody whined about the Mido that also failed (completely - 2 samples failed, stopped running even before reaching the rated depth)....

The Fortis Marinemaster went through the test without any issues, though the testers first were curious about the push pull crown as well. In fact, finally the only thing criticized on the Fortis was the missing divers extension on the rubber strap clasp (the tested watch had a rubber band). Though there has been no specific rating, the Fortis clearly won the "below EUR 1000.-" category. And (just my opinion) had they bought the Fortis on the bracelet with divers extension (above EUR 1000.-), she would have blasted away (nearly) all the more expensive watches, because *the Fortis Marinemaster and the Sinn U2 were the only 2 watches in the test matching all criteria of the ISO 6425 standard* (including the readability, bezel markings and other criteria) without any failure during the tests. Considering all watches in the test and the results, the Fortis was clearly no. 1 together with the Sinn U2.

Sorry if this reads like a rant of a Marinemaster fan - but I am a Marinemaster fan. Though I am not a scuba diver, I take my Marinemaster to the beach and into the water all the time - never had any issues.


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## dogdoc97 (Feb 13, 2007)

great post, lots of great info! dogdoc


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## DGMarnier (May 25, 2007)

I recall reading that report in WatchTime some time ago. 

Great post!!


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## sjaakb (Feb 24, 2006)

I have the MM chrono, not an issue at all. I'm going into the water this afternoon and don't have a care in the world about it. Never accidentally pulled it either. Works quite good, that and the report above should give you peace of mind..... good luck!


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## V8 (Oct 7, 2006)

I like it, no threads to cross thread, not that I've ever had that happen. Screw down is piece of mind but I don't miss it.


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## Africoz (Aug 19, 2008)

Agree. My B42 OC was my first non-screw crowned diver and I was a little sceptical at first but no longer have any doubts about the watch. If I have any complaints about the B42, it's the very average lume (obviously not a problem with the Marinemaster version from what I've read). I think the numbers on the Marinemaster dial are too large, making the dial too crowded, but that's a personal preference. Both watches are fantastic value for money IMO.


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## rubberlogic (May 4, 2009)

hmm... very interesting... anyone know where i can get the article on dat test?

edit: i think i found it... was frm a 2007 issue


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## DGMarnier (May 25, 2007)

Yes it was from a 2007 issue of WatchTimes


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## 2manywatchez (Mar 3, 2009)

As a curiosity, is the water-tightness dependent on the crown be pushed in? Or is it a sealed system that is water tight in both positions? In the later case, I could see the screw down being redundant, save perhaps unexpectedly hacking your watch and getting a false reading time...


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## slb (Jun 26, 2008)

What I wonder, is does manual-winding wear the seal(s)?
I can't help but feel guilty as I have none of those fancy winders.
Is there a schematic of the crown-seal system somewhere?


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## cnmark (Jul 30, 2006)

2manywatchez said:


> As a curiosity, is the water-tightness dependent on the crown be pushed in? Or is it a sealed system that is water tight in both positions? In the later case, I could see the screw down being redundant, save perhaps unexpectedly hacking your watch and getting a false reading time...


It is sort of a double gasket system. And, according to what I was told, the Fortis retains a small amount of water resistance with the crown pulled out.

But because *full* water resistance is only achieved in the pushed in position, it is _not recommended to deliberately pull out the crown_ while submerged.

And yes, a screw down crown is redundant. And a screw down crown with an additional lever to protect against accidental unscrewing is more than redundant.

At the time screw-down crowns were introduced, the engineering was not as far advanced to build self-sealing gasket systems that small. So the manufacturer (Rolex in that case) came up with a screw-down crown. Other system used were these awkward "canteen crowns" or a lever to press the crown in (Panerai). All old technology - in case of Panerai retained for fashion reasons.

Actually, as outer pressure increases while submerged, the watch will retain a lower pressure inside. Thus with a modern gasket system the higher outer pressure will tighten the gasket system up. Sort of self-sealing, just the opposite way a safety pressure release valve works..


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## 2manywatchez (Mar 3, 2009)

Thanks for all the details.



cnmark said:


> Actually, as outer pressure increases while submerged, the watch will retain a lower pressure inside. Thus with a modern gasket system the higher outer pressure will tighten the gasket system up. Sort of self-sealing, just the opposite way a safety pressure release valve works.


This makes perfect sense. Not that I'll do the test, but my guess is it would get awefully hard to actually pull it out under pressure.

As to leaving it out accidentally, provided you've got a hacking movement, you'd notice pretty quickly that the second hand was not working.


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