Tasked with securing the Persian Gulf, the Islamic Revolutionary Guards Corps Navy (IRGCN/NEDASA) is organized into five geographic regions, plus a handful of independent bases outside of the Gulf. These form the administrative basis for conducting combat operations and are believed to be largely equivalent to other services' 'regional headquarters'.
1st Naval Region – Bandar Abbas
The 1st Naval Region is headquartered in Bandar Abbas. As of March 2014, the region is commanded by Vice Admiral (hereafter, BG2) Mohammed Shiyari.  Prior to his appointment in June 2013, he was the region's deputy commander. He replaced the previous commander, BG2 Torabi, who was promoted to Inspections Deputy for the IRGCN. 
It's operations area is focused on the Strait of Hormuz.
2nd Naval Region – Bandar Bushehr
The 2nd Naval Region is headquartered in Bushehr, in the central Persian Gulf. As of April 2014, the region is commanded by BG2 Ali Razmjou. 
3rd Naval Region – Bandar Mahshahr
The 3rd Naval Region is headquartered in Bandar Mahshahr in the northern Persian Gulf. As of February 2014, the region is commanded by BG2 Seifollah Bakhtiarvand. 
The scope of its area of operations is unknown.
4th Naval Region – Bandar Asaluyeh
The 4th Naval Region is headquartered in Asaluyeh, between Bushehr and Bandar Abbas. As of January 2013, the base is commanded by BG2 Yadollah Badin
Its area of operations extends from the town of Dayyar in the north, to Kish Island in the south.  This area was previously associated with both the 1st and 2nd Naval Regions, but was split off in November 2008. Prior to the designation, the IRGCN maintaned an independent base at Asaluyeh. 
5th Naval Region – Bandar Lengah
The 5th Naval Region is headquartered in Bandar Lengah in the southern Persian Gulf. As of June 2014, the region is commanded by BG2 Ali Azamayi.  Prior to his appointment in 2012, he was the deputy commander of the IRGCN's 1st Naval Region. 
Its area of operations extends from Qeshm Island in the east, to Kish Island in the west, covering the islands in between including the contested Tunbs and Abu Musa. This area was previously associated with the 1st Naval Zone, but was split off in November 2012 in order focus their efforts on the cluster of islands. 
Independent Naval Bases:
Imam Ali Naval Base - Bandar Chahbahar
As of July 2013, the base is commanded by Colonel Mansour Ravankar. 
Naval Base - Bandar Jask 
Seyyed al-Shohada Training Center - Gilan
Built around 2012, this recent complex reportedly consolidated all of the training facilities used by the IRGC-N including commando and officer education.  It's location is unknown, but may be Zibakenar.
Appendix - Commander IMINT:
Footnotes / Works Cited:
1) 1,800 People Visit the Region of the Iran-Iraq War in Bandar Abbas. IRNA. 04/24/14.
2) New Commander for the 1st Naval Region Appointed. Hamshahri Online. 06/03/13.
3) Commander Sees Persian Gulf as Battlefield of Possible Iran-US War. FNA. 06/10/14.
4) Provinces Were the Biggest Reason for the Success of the Islamic Revolution. FNA. 02/03/14.
5) Iran Opens Fourth Naval Base in the Persian Gulf. Payvand News. 11/19/08.
6) Ceremony for the Beginning of the 4th Naval Region. PSEEZ. 11/17/08.
7) Members of the Bandar-e Lengah City Council Present in the 5th Naval Region. Lengah News. 06/05/14.
8) General Azamayi Became the Commander of the Sepah's 5th Naval Region. FNA. 11/04/12.
9) Where are IRGCN Naval Bases in the Persian Gulf? Entekhab. 11/05/12.
10) The Enemies' Martys Failed to Achieve Their Objectives. FNA. 07/18/13.
11) The Minister of Defense and General Hajizadeh Visited the IRGC-N Naval Region. FNA. 04/23/13.
12) Construction of Independent IRGCN Wharfs in the North of the Country. Ahrargil. 12/08/12
13) Awarding Rank to the New Commander of the 4th Naval Region. FNA. 01/28/13.