Why Msia's submarines are not deployed for SaR for MH370?

We bought the submarines for such expensive price,why can't they be deployed in the Search and Rescue(SaR) mission?
Why is S'pore offering their submarines instead?

Many people are laughing and joking:
Because our submarines cannot submerge!

Is that the truth?
Lets look at the explanation by Armed Forces chief Jeneral Tan Sri Zulkefli Mat Zin.

"No submarine is coming from our friendly country. What they are sending is what we called submarine escape rescue vessel," he said.

In a post on its Facebook page at about 9am Sunday, the Republic of Singapore Navy said that its frigate, missile corvette and Sikorsky S-70B naval helicopter has joined in the search for MAS flight MH370 since 2am, while the SSRV MV Swift Rescue submarine, which had been preparing for the operation through the night, would join in later.
Jen Zulkefli said Malaysian Royal Navy was also deploying its submarine escape rescue vessel.

It is learnt that the Malaysian Scorpène-class submarine was not deployed in the operations as it was not designed for search and rescue missions

Points from his statement:
1. What was sent by S'pore is Submarine Escape Rescue Vessel (SERV).
2. The model is SSRV MV Swift Rescue Submarine
3. Msia also deployed our own SERV.
4。The submarines which we did not deploy is Scorpene-class submarine.

Firstly, SERV is NOT the conventional submarine we are used too, or as in our impression.
A conventional submarine looked like this:

Conventional submarine (from wiki)

While SERV looked like this:

USS Ortolan (ASR-22), a twin-hulled submarine rescue ship

Surprised?
It's a ship?
Actually it worked as a package, the ship search for the unlucky submarine (or in this case, MIGHT BE submerged MH370), then only deploy the vessels (in which we all mistaken as a SUBMARINE deployed by S'pore)to rescue any stranded occupants in the subject.
How a rescue vessel looked like:

The JMSDF deep submergence rescue vehicle Angler Fish 2 aboard the submarine rescue ship JDS Chihaya (From wiki)

The submarine support vessel, MV Swift Rescue.
(From toyheaven blog)

This is how the S'pore SERV works.

How MV Swift Rescue carry out it's mission.

Also mentioned by the ToyHeaven blog:

The submersible rescue vessel, Deep Search and Rescue Six (DSAR 6) can carry up to 17 people and a crew of three, travel up to 3 knots and go up to 500m underwater for up to 15 hours at a time.

OK then, why not our Scorpene-class submarines were deployed?
You can read about Scorpene-class info from wiki.
It is just not build for SaR mission, it is specifically designed for attack.

THe S'pore's SERV (and Msia's own) was deployed, just because that there's possibility that MH370 crashed underwater and passenger may be trapped in the plane. SERV can then be sent to rescue underwater. A conventional submarine cannot perform such duty.

Conclusion:
1. SERV is not the conventional submarines we thought as it is.
2. Msia also has our own SERV named MV Mega Bakti, which already been deployed.

Asking a warfare submarine to perform a rescue mission is similar to asking a Ferrari to tow a 5-tonnes cargo.It is just not suitable!!!