It's been a long time, more than a decade, but for about a dozen years I owned a fixed-week timeshare at the old Plaza Las Glorias hotel (now the Cozumel Palace), and went every year for at least 10 years during week 12 - the last week in March. I never once lost a dive day to a Norte, but did occasionally run into some strange current days. Sure, sometimes the current would make a U-turn in the middle of a reef, or pick up to carnival ride level, and it was on a March trip that I had my one and only experience with a downcurrent on Santa Rosa Wall, but it wasn't a big deal and the diving was still a lot of fun. And I liked the weather in late March - not too hot, pleasant at night, occasionally a rain storm, but it never lasted long. And I used to like to watch the NCAA March Madness games at the old Sports Page, which, alas, no longer exists (it's now an OXO store katy-corner from Wet Wendy's) and catch the occasional Spring Breaker who escaped from the madness of Cancun. So I wouldn't strike late March off your list.