Boss Music 3
Boss Music 3 is the least used boss music. It is only played twice, both in aquatic settings where you have to fight large platoons. You first hear it from the boss of stage 3, the submarine platoon and the two turret cannons. The last time you hear the tune is when you encounter the ending of the sewer in stage 7 where you have to fight a swarm of soldiers in order to win.
This title is based on the where the song is heard in the game, the composers should be contacted for an official title. Although this is the third boss tune you hear in the game, it's actually the second boss song in the NSF file as track 11.