Translation of fortalecer in Spanish-English

There were no lights on the highway and hardly any cars, but quiet a few motorcycles and funnily pedestrians walking on the emergency lane. There was a tropical atmosphere in the air, I liked it.
On Friday we are flying to Switzerland and then on Monday we will continue to Boston, Maine, Vermont and New Hampshire. I am very excited. Maybe this is going to be a great experience again.
We returned before dusk, as we were afraid of not finding our ship in the dark. Once on the ship we decided to go for night swimming again in the open ocean. A few women on little boats approached us.