Hello Rusty,
firstly - congratulations on your decision to visit Maldives. it is fabulous!
i've recently returned to US after a year long gig as an instructor for a couple of different resorts (Viceroy at Shaviyani Atoll and Hilton-Conrad at South Ari Atoll).
the Shaviyani Atoll is north of Male and Ari Atoll is to the south.
There are over a thousand resorts of variety levels, independent dive operators and live-aboards all over Maldives, so it is hard to say with any degree of accuracy where in those atolls, you've specified, you're excursion will take you. Also, the season is of great importance when looking for whale-sharks. it was part of my job to take out guests from Conrad-Hilton resort to the southern most plateau of Ari Atoll nearly everyday to experience whales sharks. Some days we saw multiple whale-sharks and others none - that was June-July time frame. The whale-sharks come up from the deep near the plateau's edge to warm themselves.
it is worth noting that northern atolls, as a general rule, do not get as many large pelagic fish, such as whale-sharks or mantas until later in the season (the large pelagic fish migrate up north with the change of wind and monsoon - also nutrients). So if you are traveling in March/April the northern Atolls on your list will probably not be as fruitful in detecting whale-sharks as the southern atolls. Your best bet for whale-shark sighting is probably in south Ari atoll.
The trade winds shift from north easterly to the opposite direction starting mid-late April to October(ish), this means you will enjoy fairly good whether both in northern and southern atolls. I am only aware of the two atolls where i have worked, but of the two, the southern Ari atoll is by far the better of the two. it is also widely recognized among the instructor circuit as the place to teach for the experience. I am sure the other places are great diving as well - im just passing on what i have experienced and what was "considered" a rule of thumb.
Chances are you will see your whale-shark. Also i would be surprised if you don't see Mantas, eagle rays, sting rays, variety of sharks, oriental sweetlips, trevallys, tunas and thousands of fusiliers on every dive (just what comes to mind right-now).
if you have any questions, feel free to contact me.
i hope you'll enjoy it as much as i did.
Joseph MSDT, 174785
CA, USA
