This isn't a red Sub, you'll note there's no date. Look closer and you'll find the red line above 6 is an Arabic signature, that of late former President of Syria Hafez Al-Assad. This is what's sometimes referred to as the Syrian Sub, and it's an order of magnitude less common and more subtle than khanjar dials most are familiar with. Middle Eastern signatures cover a far wider range than it may first seem, Qaboos bin Said, Saddam Hussein, Muammar Gaddafi, and indeed Hafez Al-Assad all had Patek Philippe or Rolex create personalized dials for them, amongst others.
Where many Middle Eastern signatures appear on Day-Dates and Datejusts, Assad preferred sport Rolex. There are a handful of known 1665 Sea-Dwellers, 1680 Subs, and 5513 Subs known to date with this signature present. No one is certain on estimates of 1675 GMT-Masters or 16550 Explorer IIs, though both have also been seen with Assad script. There is one known Patek Philippe with an Assad dial. Research indicates that there are two styles of Rolex Assad signatures, a gloss seen more often on Explorer IIs and GMTs and this matte, mainly used in Submariner and Sea-Dweller dials such as the most famous example which sold through Ten past 10 in 2011. Researching old catalogues from Sotheby's and Christie's will reveal that both styles are seen in roughly equal measure on Sea-Dwellers, Subs, and GMT-Masters but only gloss in Explorer II.
The obvious elephant in the room here, which should not be overlooked, is that Assad ruled brutally in his term from 1970 until 2000. He frequently relied on condemnable violence to maintain his power and though he invested in building the country's education through literacy, public infrastructure, and urban centers, he would just as easily revoke his citizen's access to clean water to maintain rule. Attacks on his own people were not uncommon. Some maintain that a watch like this can stand alone separate from the man as an object of horological history. Others maintain these are morally unjustifiable. Ultimately, it is simple a 5513, one with a past that is guaranteed to be interesting, but only known in the last two decades. And in the event that you are the next owner, the story this watch has to tell in its prior two decades may just make you feel a bit better about this particular Sub. It is known from then on. Yes it's an astounding individual history, but also more emblematic of Rolex's decades catering to some less savory world leaders, all wrapped a watch that seems to wear twice as heavy. Perhaps that's why it seems to have its own gravitational pull to some also.