April to september is considered as (Austral) winter with a maximum a swell in the indian Ocean. The transition period (March-April and October-November) might be the best months (with a advantage in spring) for clean session with lots of sun but with a frequency and size less than the south-west monsoon ( May-September).
The heart of the south-west monsoon is june-july with frequent rain (but short), and moderate winds. Il is little less hot and this is the period where the navigation is the most difficult.
With the 3 different swell direction (West, South-West and South-East )in the central Atoll that receive them all, it is a period where the waves are guaranteed, except during heavy storms, (rare).
There are less boats around during the South-West monsoon, and that could be good time for South Male and Meemu atoll.