The recommended requirements are:
Maximum upgrades on shipyard for the rank
Maximum upgrades on the construction yard for the rank
HQ upgrades maxed for deployment time, view and starting resources
Maxed caiman for the rank
The execution of the build is for sea maps, and should be done as follows:
Construction yard
Emergency measures boost
1 supply center
1 power plant
2-3 barracks
2 supply centers
Construction boost
Upgrade headquarters to level 2
Assault vehicle factory
Additional power plant after gathering some resources
The boost usage depends on the type of sea map. If the sea takes up majority of the map such as in Oculus, a construction boost can be held for the entirety of the time that the headquarters is upgrading
If the map has only partial sea, then the construction boost can be held until the first infantry pop out for collection of resources, after which a scouting boost is essential to get a balanced amount of containers both on land and sea, while being able to have a fast entrance to the sea
2 shipyards (preferably in deployment time)
It is also recommended to use a naval platform in case of close sea maps, to protect against any sort of delta threats early on
Once 2 shipyards have been placed, order 4 caimans from the shipyards with a naval production boost. Once the first 2 caimans are out, use a common attack boost to boost the speed(and possibly range) of the caimans while taking resources. Once 4 caimans are out, swap back to a naval production boost, and pump out as many caimans as possible, rallying them into different areas of the sea while intercepting deltas. Approach the enemy base and attack accordingly. It is recommended to do the following:
Scout - The success/failure of the tactic solely depends on adequate scouting. If there is a naval platform present under construction, it is necessary to rally as many caimans you have to target the platform, under a gold defense boost to give the largest damage boost possible. If the naval platform has already been constructed, it is necessary to take a large number of caimans(recommended at least 8) and maneuver around while dodging the torpedoes, to eliminate the naval platform. In all cases, eliminating naval platforms is key.
Mining - Depending on the circumstances, it is possible to eliminate all enemy deltas on the water and mine the shipyard entrances of the enemy, preventing any deltas from being produced. This allows for the caimans to have free reign on the enemy coastline. It is also possible to mine the coast of the enemy where naval platforms can be placed, so as to ensure the naval platforms of the enemy are pre-damaged and much easier to eliminate.
Priorities - If it is impossible to remove all naval platforms of the enemy in time, it is also possible to attack from an unprotected side. Maps such as Cuba and Crosslake have unprotected sides which allow for a free attack from a side where there is no defense. Regardless, it is likely that the enemy will begin to try and construct defenses while the caimans are attacking. Your first priority to target the enemy defenses first before anything else. Bunkers for example construct quite fast, and are difficult to destroy once completed. Sufficient caimans must be prepared to deal with the threat of the enemy. It is necessary to eliminate the enemy construction yard first after all defenses have been cleared, to prevent the enemy from expanding inland. The caimans have good firing range which can be helped by the naval strike boosts.
Overall, if done correctly, the caiman rush ends the battle mostly in under 8 minutes depending on the map. The circumstantial requirements for success are:
Relatively low delta count early on
No/Late naval platform
Absence of level 2 shipyard for Vikings
Close distance to enemy base to allow for quick reinforcements
Scout adequately and act accordingly and take fast victories at sea