Heading up the Bay of Bengal to CCU in the 70s in a VC10, I remember our Doppler telling us we were 150 miles X track desperately trying to steer around an ocean's worth of monstrous Cbs in the dark, all flashing and banging and shaking us to pieces. I remember looking at the control system hydraulic power control unit indicators and all 11 were showing amber lights- meaning starved of oil (as it was all levitated)! When a bad monsoon moves up into that area, it can be a place very not-to-be!
There is always a westerly jetstream blowing along the N African coast which has its moments, but the worst I have always found is in the Indian Ocean- the monsoon there seems to be more powerful than other oceans, or maybe because it is my regular stamping ground.