A sea base is any base built on water. They are a good way to boost your population (for council votes and production of colony pods) and energy.
- Kelp farms produce +2 Nutrients (+1 extra Nutrients with the Aquafarm facility). They also spread on their own at times, saving you some effort.
- Tidal generators produce +3 Energy (+1 extra with Thermocline Tranductor facility).
- All sea tiles are great for taping nutrients and energy. You can have kelp and tidal generators on the same tile, without them affecting each other.
- Can be placed within striking range of your enemy's base, allowing you to get air units closer, or ships to bombard their terrain enhancements.
- If your enemy does not have adequate sea or air power to challenge you, then building at sea makes you immune to attack.
- Movement through sea tiles is faster than land tiles. So easier to get your colony pods to new location, move troops to defend areas as need be, and move your supply crawlers around.
- Once planted, kelp spreads on its own, giving you ample food. The more food you have, the faster you produce citizens to work more tiles, act as engineers, or to use in colony pods for more bases.
- Various bonuses from social settings, faction choice, secret project, and base facilities, can allow you to produce quite a lot of energy from these bases.
- A headquarter can produce endless seagoing supply ship to farm energy. Instead of ten energy supply ships spread across several bases, you can concentrate them all at headquarter and reduce ineffiency loss to zero. It's easier to get HQ to golden age this way, and a golden age would be more beneficial here than other place.
Other than the spots where mineral bonuses are found, there is a severe shortage of minerals.
Mining platforms only give +1 minerals until the discovery of discovery of Advanced Ecological Engineering gives you +1 minerals. You get an additional +1 minerals in bases you build the Sub Sea Trunkline facility. Compared to what you get from mining on land, its not much at all.
There are however other ways to get minerals to sea bases.
- Sea bases can be built within range of some land tiles, and land terraformer units can be used to build mines and thermal boreholes.
- They can also produce supply crawlers, and have a transport ship or isle of the deep move those to land.
- Other bases can make supply crawlers to send to them, and set them to ferry one mineral resource from each crawler to them from the other base.
- Nessus mining stations allow you to produce +1 mineral at every single base you have with an Aerospace Complexes, and half that for bases that do not. You get a mineral not just at the bases that have satellites built at them, but at all of them. Each base can build one satellite for each citizen it has. With sea bases able to generate so much food so easily, once you have enough minerals going in to a sea base to have a decent production rate, you can keep doing this.
- The Nautilus Pirates faction gets +1 mineral bonus from mines placed on ocean shelf squares.
A sea base is created by a sea colony pod, or if a land base is submerged in water (due to rising sea level) while protected by a pressure dome (otherwise it is destroyed). A sea base can also become a land base if sea levels drop.
Sea bases are best defended by land units (usually infantry) than naval units, as they will also count as police. A sea base can be attacked and captured directly by a naval unit, or by a unit with amphibious assault. The AI never produces naval probe-teams, so there is no need to build defensive teams.
Sea bases would benefit greatly from this as they can have kelp and tidal harnesses built on each water square, and there is plenty of open water to get to and build new bases at.
Once your population has grown higher than necessary to work every spot the base has within reach, you can shift excess people to research scientists. You can build facilities there to boost the points going to your tech research.
Once you have Doctrine: Initiative, you may build the Secret Project Maritime Control Center, provided no one else has completed it before you. It provides a free Naval Yard in every one of your bases, and +2 movement points for all your naval units.
The Nautilus Pirates automatically receive a free Naval Yard once they complete Doctrine: Initiative.