The automatic Scuba Titanium, first produced in 1992, was placed under the Prospex line which used the 4S15 caliber, in fact a re-used king seiko caliber. It marked a new beginning for mechanical watches by Seiko.
The watch had a Sapplex crystal with a date window. These 4S Scubas were only manufactured for two years but the popularity has only increased over the years and remains one of the “must haves” for collectors. The 4S15 movement is “Hi-Beat” at 28,800 bph (8 bps), is hackable and also supports handwinding.
This model was released with two choices of dial color – black, and cream. The signed crown at 3 is used for setting time and date. There’s a Tsunami picture on the back case. Model numbers are SCVF001 Black, SCVF003 Cream.
One should not forget that in the nineties mechanical watches were not as popular as they are now, and thus the re-emergence of the 4S would be short-lived. Also, as a result of the arrival of the full-scale mechanical watch boom, product lines such as "Grand Seiko" and "Credor" were to be rebuilt.
The movements Seiko installed in their Prospex editons could differ widely in every aspect, there is the 4S15 caliber movement (rated at -15/+25spd) as a refinement of the King Seiko chronometer grade 5246 movement, introduced in the early 1970’s or there is the 8F quartz - much more accurate of course.
One might suppose therefore that the prospex line consists of high end watches of any ilk. This certainly makes sense for they are all a bit toolish and have the bracelet much more dominantly integrated into the design.