I'm about to embark on a solo trip to Spain. I've travelled alone to Rome and St Petersburg (Russia, not Florida!)so I generally feel I can handle myself. I have heard that Morocco isn't safe for women alone. Is this true? I only plan a day trip there. Any suggestions? I'm not a huge fan of guided tours but....
The problem for any single traveller during a day trip to Tangiers is getting hit upon by vendors....single women seem to be big targets. If you're used to brushing them off, then you should be OK, as long as you watch for pick-pockets. But if you're only exploring for a day on your first visit, it's probably better to join a tour. You can bet they'll direct you to several spots where they get a commission if you buy there...but at least they keep the crowds off your back. If you do go on your own, remember that Morocco is two hours behind Spanish time during the summer....so make sure you take that into account when scheduling your arrival at the port for the ferry back to Spain.
My daughter (then in her late twenties) spent 2 weeks traveling in Morocco. Women traveling alone do get hassled. Every time you pass a cafe they would stare at my daughter. I got the back of my arm pinched walking 1 block, back to the hotel, one night. In some of the small stores, the male salesman would stand in your way to keep you in the store so he could get you to buy something. A taxi driver, wouldn't lift our luggage off the roof of his taxi. You probably are safe as long as you don't go out alone at night. We would go back. I didn't care that much for Tangier. To really see Morocco you need to go further South. The ferry from Algasirus was nice. We also liked going to Gibraltor.
In a day you'd only get to Tangiers, and you could well spend a lot of your time waiting and queueing to travel on the ferry (which doesn't always leave on time). We experienced a lot of pushing and shoving and waiting in line at the borders (and we were with a tour group). We visited Fez and Marrakesh as well as Tangiers and went into the Medinas (definitely glad to be with a guided group for that!) The vendors are certainly persistent but we always found them good-hunoured. I was glad to be with my husband on the streets, though - the men certainly do stare at western women and it can make you feel uncomfortable. Morocco is a fantastic experience - but you would get more out of it by joining a tour and spending longer there.
By the way, have you read the article about Morocco on this website (under Beyond Europe/North Africa)? It may give you a better idea of whether you want to go or not.