The currents here vary from day to day, I saw references to trips being cancelled when the currents made it too rough to come over here. If you are coming in by cruise ship, you might have a plan B if they aren't taking people over to the Baths. If you go into Spring Bay and are not a strong swimmer, make sure you keep to where you can touch bottom as it is easy to get sucked out in the current. If the flags are red, you shouldn't be in the water, no matter how strong of a swimmer you are.
Maybe it was just our experience, and this isn't typical, but we found the drivers in Tortola to be much more aggressive than on the other islands. The roads were in bad condition, and our rental car left a lot to be desired. As was the case on the other islands, the roads were narrow with sharp curves and dangerous switchbacks. The problems arose when you met someone that wasn't able to stay in their lane while making the curve. Also, on one occasion, a huge dump truck wasn't able to make the curve (we were behind him), and he immediately began backing up without looking in his rearview mirror. We had to quickly get out of the way which isn't easy 1000 feet up, with no shoulder. A lot of the locals will blow their horns to let you know they are coming. This usually means they are in your lane.
Since you drive on the left, my advice is to hug the left side and always be alert when you are driving. All of those things that most of us do when driving (eating, talking on the cell phone, etc.), I don't recommend doing when driving these roads.
The back roads of Tortola are quite narrow and twisty. And they do drive on the left with LHD cars. There are also people and livestock (first photo) on the road.
Tortola is very hilly (mountainous?) and the roads cover the terrain. There are many switchbacks, steep inclines and dangerous dropoffs so keep you eyes on the road.