Streetjudge, it is the same genus, no doubt, (sub)species is a different question. There are currently at least three species "accepted" by mainstay cephalopod science, the gelatinous blanket octopus,
Tremoctopus gelatus,
Tremoctopus robsoni and the palmate octopus,
Tremoctopus violaceus gracilis and its sister subspecies the common blanket octopus,
Tremoctopus violaceus violaceus. "Your" Tremoctopus and the Del Ray specimen are anatomically very much the same, but only appear different in coloration, the latter showing the distinct dark purple hue dorsally and the silver to orange, ventrally, that seems to typify
T. violaceus violaceus. The mottled, or "spotty" appearance of your specimen is a pattern I would normally associate with
T. violaceus gracilis, but you'd need proper DNA sequencing done to corroborate the evidence. Again, understanding Octopus species on visuals alone is very hard, as they have the ability to change their color, skin texture and even body shape to a certain extent, making a positive ID from a static photograph alone quite close to impossible.
@skywindsurfer, the sexual dimorphism between male and female
Tremoctopus is likely the largest of all cephalopods, much as with the closely related
Argonauta.
@chrono_war01, the Portuguese Manowar's tentacles are usually between 10 and 15 meters long, and the nematocysts will fire off a venom when in contact that causes (sometimes) severe pain for up to two hours or so, but is hardly ever lethal, bar the occasional rare reported event (in which case anaphylactic shock might be the culprit, perhaps?).
Additional trivia: juvenile female and male
Tremoctopus actually "harvest"
Physalia nematocysts to tote as weapons of self defense on their dorsal arm pairs.