Weapons

The Nimrod's weapons bay can hold over 5000kg of weapons. It has been redesigned in the MRA.4 with two bays separated by a sonobuoy tracking sensor.

Sea mines
Depth charges
Stingray torpedoes
1000lb bombs
AGM-84 Harpoon anti-ship missile
The MR.2 can carry Harpoons in its weapons bay. The MRA.4 will be able to carry four underwing missiles.
AIM-9 Sidewinder/AIM-32 ASRAAM
At the time of the Falklands conflict in 1982, a number of Nimrod MR.2s were modified to carry the AIM-9L Sidewinder, two under each wing. The Nimrod MRA.4 will have double the capacity.
Sonobuoys
The MRA.4 will be able to carry 42 sonobuoys in four 10-shot rotary launchers and two single-shot pressurised launchers, which is a three-fold increase over the MR.2.