I think it's spelled Tobago.
It is well discussed here on SCUBABoard, try a quick
Tobago is two divergent worlds. the South end (Pigeon Point) has been dived for many years by European day-trip divers and cruise ship visitors. There is a lot of good diving as the island itself is sparsely developed near the seashore, meaning very limited siltation and run-off... that's what kills the reefs, so the place looks pretty good. That combined with the fairly stiff currents will keep things healthy.
The South end is well populated by day dive-ops, bars, restaurants and everything a cruise ship port would need. I would put it fairly low on my scale of "places to worry about crime", but all of the aforementioned decrease dramatically as you head north and away from the airport/cruise ship areas.

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The North end (Speyside/Charlottesville) is just recently becoming well known among SCUBA divers although it attracts 5x more "bird watchers" from England than divers. The people up North are the true hillbilly farmers, and I prefer their company. Real honest to Pete Rastafarians.
The North end is an excellent training ground for the Galapagos as there is no stiffer lateral currents combined with downcurrents to be found anywhere in the Caribbean. Your divemasters will guide you well, decide if you are ready, but understand that comparatively, Cozumel is a gentle breeze. You go to the North End for the roller coaster rides- as most dive operators have no clue how to locate the remaining Mantas~ best done as a night dive which very few visitors have the stomach for. This isn't a plop in the pool, it is the black sweeping ocean where you better have yourself sorted out if you're going for a swim after dark.
Tobago is generally a pita to get to and I would advise spending any connecting flight connections through Trinidad squarely within the airport. There is no diving there and likely nothing you're looking for.
You will find excellent road surfaces that are unlit and unstriped, with no reflectors as the switchback through the mountainous Northern half of the island. It is one of the few islands where I suggest that competent drivers should rent the right-hand drive vehicles and go explore this beautiful tropical Caribbean island. Drive
very slowly and don't be a statistical idiot.
I rate Tobago's
total island experience within "My Top 5" of the Caribbean.