Whereabouts are you planning to go - the Atlantic or Mediterranean coastlines?
Or are you going to attempt that rally from Plymouth down to Banzul (Gambia)? A friend of mine who completed it in 2005 talked about, slightly further south in Mauritania travelling down Atlantic beaches a 100 miles plus long. A tad easier, there're not too many roads down that part of the world!
Any rate in Morocco the fishing tends to improve, along that Atlantic coastline, as you get further south. And, although you've got the on shore Trade winds and some big seas to contend with they seem to catch things like the Bream species, Bluefish and Conger Eels from close in. And offshore from Casablanca and Agadir they encounter White Marlin (in the Summer and Autumn months) and a variety of Tuna species. More 'exotic' things turn up from the beach further south and I know there're French companies that organise trips to there and Mauritania. Might be worth 'googling' to find some links? Try 'Le Maroc, pêche de rivage'.
Alternatively, if no one else responds you could try a post to the Moroccan forum on http://tripadvisor.com. That should bring up a number of posts on fishing.
I've not fished there myself but do remember watching a John Wilson (huh huh ho) programme in the 80s or early 90s in which he fished the dune coast near Dakla, close the the Mauritanian border. (Since, it has become a war-zone and then a UN-administered peacekeeping zone; I'm not sure of the status now). As I recall, he had a lot of luck using beefed-up beachcasting gear from long, sandy beaches and into a pretty steady wind, catching fairly large rays, guitarfish, a lot of the species that appear on the Gambia forum.
Hope it's of some use. You might be able to track down the video.
Read the Gambia section for an idea of what its like.
I have traveled up almost to Dakar , Senegal ( used to be end of Paris - Dakar rally) and the fishing is the same as for Gambia.
By all means take a travel rod but I would suggest a beach-caster rather than a spinning rod.
If you don't spend to much , leave your gear with a local and watch his eyes light up !! Costs me a bloody fortune!
Just got back from 3 weeks fishing in the W.Sahara,from Mirleft to Dahkla.Had plenty of fish,but no real size ,spotted bass and goatfish up to 2.5 kilo being the biggest,giltheads around the same size being caught as well as the chance of a big corbine.The weather was pretty awful ,overcast with strong west nor west winds most of the time,the locals reckoned that in the next few weeks things will improve and the bass ,sar+dourade fishing should be good till Oct and then again at the beginning of the year.Standard surf fishing gear,I took a Century SRE,coupled originally with an abu 6500 but after discovering the abu wasnt holding enough line(you can wade through surf 70-100 meters to get on a sandbar)started using a Penn surfmaster 850 with braid that seemed to do the trick.Hope this helps PM me for anymore info as I have been down that way a fair bit in the last few years. MG