Bitters are made in Trinidad. They are a special blend of herbs and spices that only 3 people in the world know the recipe. Of them, they only know a part of the recipe. Normally, they are used in mixing drinks (alcoholic). You really can't drink it straight. The gentleman that created the recipe had what we would know today as GERD or acid reflux. He needed something for relief and found the blend after years of trial and error. We took an excursion there when we visited Trinidad. The aroma in the plant was magnificent. You can also use bitters in cooking. If you've had Jamaican jerk, it is similar, only no heat from the peppers.
A liquid seasoning distilled from herbs and spices used in cooking and bar drinks, like Bloody Marys. Very strong and bitter, as the name suggests, but adds a wonderful flavor in minute amounts. A dash in a glass of club soda (or Sprite) has a calming effect on the stomach.
I can feel for you. I can get nauseaus from a rocking chair, so I get particularly worried when I get on a ship. It kept me from cruising for years. But I now get by with generic Dramamine. I take it before the ship leaves the dock. The adrenaline from the new experience will keep you from getting sleepy, if you are prone to it (I'm not.) But they also have non-drowsy Dramamine. Frankly, I think the stuff is a life saver. Definitely a vacation saver. After about 2 days at sea, unless the sea gets rough, I am fine. You get used to it.
When you go diving, be SURE to take another pill, even if you have been fine for a day or two. You need something that is going to last at least 4 yours. If the rocking dive boat doesn't get you going out, climbing back on with the exhaust fumes from the motor in your face will, if you haven't taken precautions. Be sure to eat a banana or something between dives too. Nauseau is MUCH worse on an empty stomach.
My husband and I just got off the ship yesterday, and we had to take Dramamine today because the house was rocking! See, you do get sea legs! Have a great trip, tell me about the diving when you are done, and take the pills before you leave port.