I know it may sound a bit crazy (as usual) and it may not match vikings time setting but since we have all mixed in our game and will new world with islands and continents we may think of ships in our game.
so. once you reached level of realm you can start building of high lvl ships. not like small sailing boats like now but big ships of different kind, which may have a cannons. so such ships need a captain - one why showing the way. helmsman - one who following this way. watchman - one who sit on top of the mast and looking for other ships in telescop. cannon man- one who reloads and shoots with cannon. skipper - one why controls sails.
ships can be 4 types:
1. Heavy - can have avarage speed but need long time to speedup, they have heavy weaponry (maybe 10 cannons or so - 5 each side), lots of cargo space
2. Avarage - they have fast speed, avarage speedup, avarage weaponry (maybe 4 cannons - 2 each side) small cargo space.
3. light - very fast speed, fast speedup, light weaponry (maybe just 1 or 2 cannons - 1 on each side), no cargo space at all
4. Cargo ship - only used for transportation. huge cargo space, no weaponry, avarage speedup, low speed.
(however there can be subtypes for exmple 3 types of cargo ships and so on with different capasity, or maybe 3rd type of heavy ship you will have to build like one month or something cos the higher quality boards and nails you will use the bigger defence level of that ship is).
ok now you may ask what the hell with speed and all that....
Wind and Currency
speed can be detemined by wind and currency, so even if your watchman saw 10 enemy ships and you in minority of one still you have a chance to run away from those 10 if you catch right flow and a wind. speedup determined by weight of the ship and flow, and speed by sails and wind. (and combination of those) sometimes if you have oposite flow but wind in your direction your speed with depend in straigh of both wind and a flow. yes, they can be different. Maybe somehow helmsman will feel the flow and will be choosing the way he want to go (not forgeting of distination given by captan) but wind can be unpredictable and skipper have adjust sails accordind to wind.
Also we have an idea of different continents have different resources, so this will motivate trading between realms and those who are not strong enough to become a realm can become pirates, and rob a caravans. or somethink like that.
Vision from telescop can depend on mast hight, so heavy ship has highest mast and watchman can see fuitherst. so its good to have one heavy ship just to see as far as possible and predict the fights however in this case you will need more time to change your direction if enemy in greater numbers.
Low speed need 1 sail up
avarage speed need 2 sails up
fast speed need 3 sails up
very fast speed need 4 sails up.
so if you accompany the cargo ship your all ship must have only one sail up to move with the same speed.
also you cannot change direction of ship by clicking mouse in different direction. to move your ship around you realy need to move it around by the wind or oars or it may have very little minimum speed by itself.
Sea battles
If you understand that there too much enemies who are chaising you and you are sure you gonna loos then all of you can teleport to your campfire, and all your ship with all your loot will go to enemy ass a trophy, but once you ve desided to fight you cannot escaped from fight untill it finished. you can escape by jumping on safeboat and swim away a little and then teleport leaving all your mates behind, then you may face a panishment for that.
once two ships are very close to each other players can board another ship and start fighting in normal way. if one of the ship has beed destroyed by cannons then all players will appear in the water but they still remain in the fight. but once they are in water enemy cannot kill them (except archers). to be able to kill they have to put small boat on water and approach to the player who is in watter and start fight with him, however this player can win the fight and capture this boat and escape from fight (it wise to escape fight on small boats once you understand that you gonna loose battle and swim far enough on boats to teleport at home). you enemy tho may choose not to fight with you directly after your ship has been destroyed, they can just get all floating loot and go away.
so you have three scenarios:
1. you can teleport home just before fight starts and leave all your ships behind
2. you can teleport after your ships have been destroyed.
3. you can all die
Also you have a chance of drawing but ships remaining may help you not to draw, so like swiming chests or boards will help you not to draw.
Gunpowder
why cant we have gunpowder if we have matches already???
gunpowder maid of wood coal, saltpeter and sulfur. all other stuff we already have all we need is saltpeter, which we can get from mineral called nitrokalit which can be found in mines.
as more quality of gunpowder and cannon/cannon balls metal we have the more damage level is.
Cannons
here is a recepie from old time of how to malt cannons and all ingredients we already have. here we go....
How to cast cannons?
At first from a wood or from iron was made long (longwise a cannons trunk) a rod. This rod was stacked the ends on two racks. Rotating a rod by means of a tap wrench, cast a straw bundle over it. Then this bundle was covered with several layers of clay. Each layer of clay was dried on air. To clay structure woolen threads, a hair, and the grounded dry horse manure was added. On the last layer of clay the prints of ornament or texts which the trunk of the ready gun had to have can be put. So thats how you get model of an outside part of a trunk (false model).
After final drying of model, you start production of a casting mold. The model was oiled with animal fat and vegetable oil and then applied on it several layers of greasy clay with additives of a hair and the dry grounded horse manure. Each layer was dried long. So thats how a casting mold was produced . Form 200 — 300 mm thickness. Animal fat and veg oil were necessary for formation of an insulating layer between model and a form, and the wool, a hair and manure which were burning down when filling metal formed a little channel through which of a form gases were removed.
The form was strengthened with crossed hoops. On them imposed longitudinal iron bands, and they also fastened with several more crossed hoops. Then beat out with a hammer a rod with a straw bundle and put a form vertically. Threw logs of firewood in the space which is earlier occupied by a rod and a bundle. Under the influence of heat in a form the insulating layer from animal fat and veg oil was kindled, and the remained clay was burned, easily broken and deleted from a form.
The rod for formation of an internal cavity of the cannon was produced as well as the first one: by rotating it on two racks, wound it with hemp, covered with a dense layer of clay and by means of wooden templates gave it the outlines corresponding to an internal cavity of a cannon trunk.
After drying of a form and a rod the rod was inserted in a form, precisely centering it. Then carried out a groove from the furnace to a form and let in the molten metal. Such molding of cannons was called slow. Later it was replaced by fast molding.
so yes, we will need a special foundry furnace, on quality of which Q of cannons will depend.
Ship building
You cannot just build ship in the forest right? you gotta build big shipyard near the sea. then you start building, but its not like a house where you have like list of materials and thats it. you build it with parts. first you build a skeleton of the ship, thats how you know what ship it is, then you use boards for facing, then bring already crafted somewhere near by- steering gear, anchor, then you build a mast, then bring sails and robes, then crow nest, then cannons and cannon balls.
Btw sails you carft either on special station or simply by connecting peices of cloth together using sowing skill. Quality of cloth determins speed or something like that, im not sure.
after ship is done you have bring a lots of logs and put them in front of your ship so that ship could roll on those logs directly to the sea. if you not succeed you gotta lift ship up again, put more logs and try again. To lift ship up and down you gotta use special lifting mechanism, which can be installed to shipyard alike the one a windmil has. so its separate mechanism you gotta build and it also can be use to repair damaged ships. so before to repair you gotta roll it back and lift it up, then you can fix it.
there can be a special skill like - shipbuilder.