Submerge and Support is an upgrade for the Monkey Sub, first released in BTD5 Generation. It adds a new Submerge targeting option that stops the Sub from shooting darts but instead produces green sonar pulses that decamo bloons. The Submerge and Support upgrade follows a similar lineage of upgrades in BTD5 Generation games compared to BTD6 Generation games, with minor differences (specifically the Barbed Darts upgrade in BTD5, and the Longer Range upgrade in BTD6).
The following pages correspond to the Submerge and Support upgrade:
- Submerge and Support (BTD5), the third upgrade of Path 1 for the Monkey Sub in BTD5.
- Submerge and Support (BTD6), the third upgrade of Path 1 for the Monkey Sub in BTD6.
- Submerge and Support (BTDB2), the third upgrade of Path 1 for the Monkey Sub in BTDB2, nearly identical to its BTD6 counterpart.