STEELDIVE SD1975 300m Diver comparison to a Seiko Prospex 200m Diver.
Recently, I purchased a STEELDIVE SD 1975 300m rated dive watch, powered by a Seiko NH35 automatic 24 jewell movement. The STEELDIVE SD 1975 300m features a ceramic bezel insert and a low domed sapphire watch crystal. This "Honeycomb" model came with a rubber type typical diver's watch band, perfect for diving (well maybe-more on this later). There is a screw down crown.
First glance, very well made, machining tolerances appear very good. Component assembly has been well-done, ie evenness of construction components is better than my Seiko Prospex 200m diver (almost 3X expensive-retail price). Or the Seiko Baby Tuna is X2 more expensive using an average competitive internet price on the Seiko as an comparison.
The top image shows the assembly of the hands of a Seiko Prospex 200m "Baby Tuna" dive watch 4R36 movement. The lower images shows the hands assembly of the STEELDIVE SD1975 300m dive watch NH35 movement. Both are taken at approx. X4 magnification. There are NO discernible differences between these two watches.
The crown positioning within the "Shroud" of the Seiko "Baby Tuna SRPE87K1 with a 4R36 movement. One can see the shroud is closer (but not touching) to the crown on the righthand side of the crown. Personally for me this is NOT a big deal as long as the crown ISN'T touching the shroud in any way to restrict it's smooth movement.
The crown of the SD1975 300M diver from STEELDIVE is perfectly located centrally to the cut out section of the shroud, as can be seen in the above and below images.
Mostly good shroud alignment on the Seiko baby Tuna
Some very small gap as can bee seen on the left hand side of the crown in the Seiko Baby Tuna.
No such gap on the STEELDIVE watch.
Watch Face Finish of the STEELDIVE Watch
Looks pretty darn good to me. Just as good as a Seiko! If not slightly aesthetically better. People want the funky colors! Keep them coming STEELDIVE!
Polishing?
Lovely polishing where small details count, as on the watch lugs. STEELDIVE SD1975 300m Dive watch.
How is the Diver's minute maker presented?
This is the Seiko Baby Tuna
Yes, it's very dirty as I wear this watch almost 24/7. One can see that the phosphorescent material is protected via a very small glass and metal port.
This is the ONLY luminous paint featured upon the bezel of the Baby Tuna from Seiko.
There is no such (apparent to the naked eye) protection in the STEELDIVE SD1975 300m diver.
The longevity of the phosphorescent material will depend entirely upon what binding material is being used to secure tis material to the indentations of the bezel. (see below).
Setting the Time
On setting the current time (standard method for N35 movement) I found the crown operation to be smooth (therefore the threads were well made), and easy to lock back down again, as easy as my Citizen Promaster 300m saturation Diver's watch! (which by the way is an outstanding dive watch). The bezel markers align perfectly on all of the second/minute markers.
The same could not be said about the crown of my Seiko (bought from a physical jewellery chain store) for which the crown was always difficult to manoeuvre into engaging the thread to screw back down the crown into place.
Now how about that killer luminous/phosphorescent dial of the STEELDIVE SD1975
It's VERY COOL!
It's hard to see (from this image) here but the main markers are, to the human eye, a lime green, a very intense blue as well.
Three (3) tone luminescent dial markings. Let's see how long they last (I mean here, resistance to abrasion and loss of material) because they have been applied to the indented markers and numbers of the bezel. Although so has the paint on my Seiko and it certainly has taken some abuse. The dial is easily read either in bright light or in total darkness.
Here are my test procedures, which mimic exposure from a standard scuba diving torch, illuminating at the surface of the crystal in a dark environment:
Expose watch for approx 30 seconds and then attempt to read the dial markers until a legible reading is not possible without further exposure to a light source.
Now everyone knows Seiko is KING of Lume when it comes to the very little light (from any source) is required to generate long lasting phosphorescent decay times. ALL others (Citizen, Casio, including Steel Drive etc etc.) require more than a fleeting few seconds to get that lume to have decent decay time, some are worse than others.
A mere second or two is all that is required to get Seiko's lume to glow like no tomorrow! This was taken with a very short 2 sec exposure (showing the 12hr marker on a Seiko baby Tuna). Sorry, it was taken hand held so a bit out of focus!
*Results of the Decay Duration from the STEELDIVE SD1975 are as follows:
The duration of the luminescence as witnessed by the human eye, ie the decay time is approximately well over 4 hours with easily >1 hr duration after exposure to light (30 seconds).
*I know this is somewhat subjective as it depends also upon the optimal excitation wavelengths being present in the LED source for maximal excitation of all material.
Wearing Comfort Test.
This test is dead easy and anyone who isn't doing it like this has no idea! Ok just joking!
Simply wear the watch to bed. If a watch is going to become uncomfortable, it will be immediately apparent during one's sleep patterns. Possible problems experienced could be anything from cutting off one's circulation in the lower wrist to impingement upon nerves resulting in the "pins and needles" felling when certain nerves close to the surface are "stimulated".
If you can wear a watch to bed without ending up with bruising of the wrist, a painful wrist etc etc. then it is comfortable to wear anytime. During sleep we may move in unpredictable ways which are not biased by conscious thought. ie purposefully moving one's arms in a way which would allow the watch to be comfortably worn. See what I'm saying?
So what were my results?
No problems for my wrist (left hand). As apposed to trying to wear (and they warn against this) my Citizen 200m Aqualand diving watch to bed; a totally unsuitable watch for daily wear IMHO due to it's sheer bulk (this is a tool- not a daily wearer IMHO).
Now as to the construction, let's look at it at high magnification (up to under X4 magnification using my trusty Olympus lenses).
The Watch Crystal What is it?
The SD1975 300m diver is supplied with a:
Domed Sapphire crystal
Disadvantages: The dome, if not anti-reflective coated will reflect other images like no tomorrow.
Domed watch crystals can show undue reflections if not coated. This watch crystal is uncoated. A coated crystal would "bump up" the manufacturing cost.
Sapphire is not as "tough" as mineral crystal, ie it could be more susceptible to impact damage.
Advantages: Super scratch resistant (hardness 9 on MOHs scale, ie one down from diamond!).
A dome will resist pressure greater than a flat plate of any given material (hence domed ports on submersibles)
How is the Watch Presented and Warranty?
However there is a record taken (I hope) within the watch box, an international warranty card (looks like a credit card!).
The STEELDIVE SD1975 came with a nice little box to transport your dive watch within your dive box of gear. It is foam lined and can be attached to a lanyard at one end.
The box contained the International warranty card and manual. All components of the box were carefully packed. (see my "first unboxing video ever on @BushCampingTools
STEELDIVE
Toughness Testing:
LOL! It's a dive watch so..........They are meant to be tough by definition!
Easy give it to your kid to wear for a day! See images below.
More videos to come check the channel!
Overall as you know I DO NOT make product comparisons, I have only taken the liberty here and ever so slightly because the 2 watches are vaguely similar in size, weight and function.
As far as using this watch for diving then I would only use it for SCUBA after testing with a another "well known" dive watch brand and or Dive computer. I always use backups
A Note to STEELDIVE
If you are listening STEELDIVE, I would like to see some sort of international certification (eg ISO) of the diving rating of 200m and 300m. I know this is written in your booklets/manuals but I'd, as a SCUBA diver like to see what Seiko has done and state an ISO certification for these two depth rated watch models you produce.
I am aware this would "Bump up" the retail cost but if the watches were set to be competative still under the cost of similar Seiko or Citizen watches, then this WOULD ADD value to what is clearly a "value for money" dive watch.
