A momentum altering system comprises a transportation device configured to transport the momentum altering system towards an object moving through water. An engagement device is configured to attach to the object when the momentum altering system is transported sufficiently near the object. At least one decelerating device is connected to the engagement device. At least one decelerating device is deployed by the engagement device after the engagement device attached to the object. At least one decelerating device includes a plurality of parachute sea anchors that produce drag when pulled though water thereby altering momentum of the object.