If you look at satellite imagery it looks like you have very high terrain to the west of the runway. The water would be the primary area available for a climb back to obstacle clearance altitude. Looks like the MAP just routes you with sufficient time to climb to the MA altitude.
As Alexander already said in his answer, the turns over water are executed to gain enough altitude before turning back over the terrain.
(left: RNAV-A, right: RNAV approach chart).
The difference between the RNAV-A approach and the other two (RNAV and LOC) is the required minimum climb gradients for these two approaches. You find them at the bottom of the ...