While you are playing about with the boats...... I cannot find any info at all on unit 488 (SPB Mk.III) it uses the same photo as the PBR Mk.II. Googling "SPB Mk.III" or just "SPB" retrieves nothing worthwhile
http://www.navypedia.org/ships/usa/us_sc_pbr3.htm
lists a PBR Mk III in service 1968 - 1973 but that date may be manufacturing they do say there was some "discarding" of those boats in the late 1980's which would kinds-sorta fit with the date range for U488 now so this may just be a mistype.....PBR / SPB.....IDK but I do know when we released the Windows version of the game U488 was a PBR Mk.II. That said another source says PBR's were only made as Mk I and Mk II.........don'tcha just
love OOB work.....?
https://www.militarymachinesofameric...ver--pbr-.html
* turn your sound on when you check that webpage

....... I hadn't heard Fortunate Son in ages