One of the most remarkable aspects of the northern coast of Brazil from Natal to Sāo Luís is that is almost entirely low-angle sandy beach and sand & mangrove river mouths with relatively few rocks and reefs. There are some rocks and one place in particular that I know of with a nasty bit of sharp reef (at the point in Barra Grande), but overall it’s a very friendly coast from a geographic point of view. What you will see on any given day depends a lot on the tide, since there is a 2-4m tidal range.