If you get a chance to touch your feet on African soil, take it. While I am not the sort of person who counts the places I've visited, the ability to check off a place that counts as Africa and Arabia had me hunched over my passport like Gollum saying "My precioussss". I don't totally know why. Whatever the reason, you should never turn Morocco down.
Our chance came two years ago when we did The Iberian Blitz. Honestly, it was the part I was most looking forward to. Taking a ferry across the Straight of Gibraltar to Morocco is a very common practice with tourists who find themselves in Southern Spain. As odd as it felt to go from Europe to Africa/Arabia and back again in a single day, it is totally possible. While I've only been to Tangier, I will say that Morocco is a very kid-friendly country. Not because there are kid menus and playgrounds, but because of kindness and hospitality of the residents. Just as in Paris, children are a welcome part of life. We had no reservations taking the kids with us. Their basic vaccinations were good for a quick day trip.
So, what do you need to know about visiting Morocco for a day?
1. The voyage from Tarifa, Spain to Tangier, Morocco is roughly an hour. The more reputable ferry companies have an immigration officer on board so you can enter and exit the country with reasonable ease. (No visa is required for visits under 3 months.) Another reason to sail with an upstanding company is that different countries have different safety standards when it comes to acceptable sailing conditions and engine room maintenance. Research which one you feel the most comfortable with should terrifying squall break out in the middle of the sea. (I'm speaking from both personal experience and as a merchant ship's officer's daughter.)
2. Hire a guide. Unless you are fluent in Arabic and knowledge of Moroccan culture, then you can skip this part. Otherwise, hire a guide. If you try to wing it, the odds of you being overwhelmed and not having fun are way greater. Sure, it is kind of lame and you do feel a little hustled by the end, but I really think it is better than not. (Believe me, I loathe all touristy things. Never been on a cruise on principal. So there.) Ask around travel groups and use TripAdvisor for the best company to use and what you will see while you are there. The company we used had a little route that took us around Tangier: Camel rides, Cave of Hercules, shopping in the local market, and a late lunch in the Casbah. The price was reasonable for the service and we felt like we got a nice sampler of what Tangier had to offer.
3. Bring cash. Most of the vendors and street hawkers only take cash. Thankfully, most will accept Euros (this is how common European day tripping is). We didn't bring nearly enough cash as we are so used to using plastic when we travel. Because of this we had to pass up many cool souvenirs on account of us not having enough money on hand. Between paying the guide and dinner for the four of us we managed to come away with a little lamp and a few wooden camels in the end. Kind of sad compared to what I actually would have liked to have brought home.
4. If you opt for the guided tour of the city, don't shop at the markets you get "taken to". More often than not the guide and shop owners don't have your bargain hunting as a priority. Shop with the street hawkers. The price is better and the products are the same. Be prepared to haggle and negotiate for all prices. Almost as soon as we arrived in the country we were told "Nothing has prices on it. Get ready." Some of us enjoyed this aspect of the culture more than others. (I found it stressful, Scott found it "fun". Make of that what you will.)
5. Be prepared to want to return as soon as possible. This place is magic. The people are incredibly kind and welcoming. The food is amazing. (Hello, olives!) The architecture and art is glorious. You will tell the shopkeeper "Inshallah, we'll be back soon" as you head out the door to your boat back across the Straight. You will smile at the look of shock on his face and his misty voice when he asks you "How do you know Inshallah?"
You'll be back. You both know it.