We christened them 'Disco boats' and found them thick on the
water 2-3M
offshore and again at about 10-12M
offshore, but not a significant problem in between.
Regarding the Moroccan Coast generally and Rabat in particular, based on our own trip through there in 2012, I would argue that the Pilot Book (like most/all of them) overstates the difficulty of getting into the Bouragreg River/Rabat Marina. If there are strong onshore winds/big swells running into the entrance you wouldn't want to try it, indeed you want to be heading offshore, but we entered and left in a WNW F4 and 3 - 4' swells with no problem.
We called up the marina on the
VHF and they sent out a motorboat to 'lead us in' near high tide, though we've felt our own way in to much scarier entrances unaided.
Once inside the river there was loads of
water, the marina's clean, friendly, well maintained, very secure (both weather and personal) and inexpensive too IIRC, they don't even surcharge catamarans? We were met on the arrivals quay by the Customs/Immigration Officials, who were thorough, but polite, prompt and very professional - perhaps an hour tops?
From the marina it was a short walk to the metro trains/trams into Rabat itself - far and away our favourite place in Morocco - or a slightly longer walk (a bit over a mile?) to a major railway station, from where we travelled by clean, efficient and incredibly
cheap trains to Fez, Casablanca, Mohammedia and Marrakesh.
Don't be put off by the Pilot
Books, Rabat was a real highlight of our
Atlantic crossing.