Creating a Port/Harbor/Dock.
General Information
A Port/Harbor/Dock could be created for many purposes. As a building it could be in a fixed position, similarly to the way the clan castle is in the beginning. Once reaching a certain level (like level 90) a player can be given the opportunity to build his/her port. The building can look demolished at first instance and cost about 6 000 000 gold to be completed.
This type of building can be used to create a whole different realm and aspect of the game. On one hand it can be used to bring in new troops like mercenaries. On the other hand it can be used to create different forms of attacking and resource gathering (its resources can be exclusive to the port and its functions).
BE ADVISED. An analytical explanation of a port follows. If you want a very simple version of a port scroll down to the end titled "Another Option".
Resources
In order not to complicate the game too much it might be a good idea for it to only have one resource, food. This resource can be used to create the units offered by the port. Food can be gathered through creating fishing boats and attacking other ports. Fishing boats can be upgraded to a certain point like the other resource buildings.
Port Capacity and Troops
The Port/Harbor/Dock can have the capacity to hold a certain amount of troops with each upgrade. The troops that the port holds are only the ones that are donated (acting like the clan castle). Some of the troops that it can create can be Vikings, Spears, Knights etc. The troops that are created should only be held on the dock of the port where the ships would also be. All troops in the port and dock are dedicated to sea battles.
The port should have a dock where it keeps its ships and troops. The ships are used to transport troops and attack. Ships can be created through the use of gold.
Port Buildings
Port buildings can include the port itself acting like a clan castle. Then a dock for its ships that can be upgraded to hold more ships and troops. Then of course its defences. The player can choose where to place the defences. Some will focus on ships and others on troops. However, instead of using buildings for defence it might be better to be able to dedicate soldiers instead. On one hand to have limited buildings for attacking the ships and on the other have troops on the shore to defend against the troops that are being deployed for the siege. This might be preferable given that there is limited space.
Choosing How to Attack
One of the greatest features of having a port/harbor/dock could be the possibility of choosing whether to attack a clan either by sea or land. If attacking by land then the regular rules of the game apply and the port plays no role. The attacker will play normally with the only difference of seeing the port but not being able to attack it. If attacking by sea though then new rules apply.
Attacking by Sea
You can only attack by sea by using boats. Some boats will be for attack and some would be to deploy troops on the shore. The aim of the attack would be to use the attacking ships to destruct/destroy port defences so that the troops may be deployed on the shore and lay siege. Siege would be accomplished the moment the port is taken over. If the siege is not successful then the defence is successful. However if the siege is successful then the defender will have another mission to regain the port by sending troops. This would be an entirely separate battle. The longer the siege is held the more bonus loot is gained up to a certain limit. The siege can be lifted at any time to make sure loot is held.
The point being of all this will be so that the attacker is able to send more troops into battle to defeat someone's clan and to also gain loot in a separate way. This way if someone has successfully taken over the shore, then he/she can attack by land by using both army camp troops and surviving troops sent by sea in a given time period. If the defender does not regain the shore then the attacker might have the ability to replenish his/her troops that died in battle.
The moment the land battle begins (after a successful siege), the troops deployed on the shore will automatically attack and the attacker will manually send the other troops just like he/she does regularly.
New Mission
This aspect of the game can also create new fixed missions, where by one needs to lay a successful siege and then attack a clan to gain the loot and win stars.
Another Option
Another option would be to keep the port and clan separate. This way you simply choose whether you want to attack by sea or land. The port would have different resources, units and buildings. It can also give you the option to transfer some troops to the regular clan. In essence you are creating a whole new battle field. This would be a very simple way to make a port available.
Or else it can be created simply to bring in new units. This way the port can act as a building that brings in troops from a foreign land. Then slowly slowly it can develop into something with more purposes. Similarly once again to the clan castle.