A submarine that has problems diving?
John Berthelson of the Asian Sentinel has given us something more to think about here.

The manufacturer says the KD Tunku Abdul Rahman has successfully completed sea trials following “scheduled maintenance”. See statement here. – Photo by DCNS.
So far, 10 Scorpene subs have been ordered from DCNS – two for Chile, two for Malaysia (at a cost of RM3.4 billion) and six for India. DCNS designed the Scorpene and developed it jointly with Spanish naval shipbuilder Navantia. The second Scorpene for Malaysia, the KD Tun Razak, is expected to reach Lumut in the middle of the year.