Παραθέτω εδώ το post από το watchuseek για τις κορώνες των Fortis.
https://www.watchuseek.com/threads/fortis-b-42-marine-master.279285/cnmark
2,078 posts · Joined 2006
#2 · Jun 30, 2009 (Edited)
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.
