A tub shaped metal object/ship wont float?

[Cassowary]

Hi I'm new to this game and sorry if this was asked elsewhere. So no matter how big I made the 'tub' (increase volume : mass), it won't float, which should, on Earth. I did some search and noticed I can change planet properties in game configuration, but an object is acutally easier to float on Neter than Earth.
So should I consider that water actually can go though two attached blocks, so a ship is actually full of holes, because it visually is?

[AOrocks]

you have to use an air pump, or all closed things will be filled

[LemonHeroman]

Sadly this game doesn't simulate in real life physics completely. By completely, I mean this..
In Real Life:
-A tub (Like you're mentioning..) floats since it displaces the water...
In From The Depths:
-ANY enclosed (Or a hollow inside with no holes or openings to the air or water) will sink unless you use an Air Pump (Like @AOrocks said...)

[Cassowary]

thanks for the info, it floats now. and the effect is the same no matter how many air pumps are used? It seems one air pump is enough to let my 70*20*50 metal ship floating, and the draft won't chage if I add another 20 pumps

[Citizen Joe]

Only one pump in any enclosed secton is enough to displace all of the water inside and grant maximum possible buoancy for that volume. It is, however, a good idea to have two or three pumps in larger compartments to prevent flooding in case one gets blown up (another pump takes over if the first is destroyed)

[iSheep]

In the stock settings of FtD, metal blocks are denser than water and will sink unless using air pumps as above to create buoyancy using engine power.

Alternatively you may also add positive buoyancy to the tub by using composite materials to lower the average density - mix in light alloy and wood parts to non-armored parts of the boat and it will float by itself.

It's also useful to create double bottomed hulls and torpedo bulkheads within the tub, which can be used as buoyancy.

[Goobs]

Generally speaking, for an object to float:
The object, plus the space inside, must weigh less than the weight of the water it occupies.

So, to get a chunk of metal to float, you need to fill it with enough air (air pumps) to offset the weight of the metal in the water.

To keep something heavy afloat after some jerk pokes a hole in it, seperate the hull into seperate, (I do lightly armored compartments), each containing a water pump.
Compartments with essential parts and materials (engines, ammo stores and resources) can be more heavily armored with ERA armor, shields and layered metal.

Getting something to float is only hard once. Getting something that can stay afloat, and keep fighting, is where the game gets really fun.

[Pak0tac]

i did menaged to make wooden ships to sail without air pumps, had to make their bottom to be shallow and wide, like a floating raft, but with borders and cannons on it

[Mavis]

Originally posted by -=DustY=-:

i did menaged to make wooden ships to sail without air pumps, had to make their bottom to be shallow and wide, like a floating raft, but with borders and cannons on it

wood will always float no matter the configuration due to it being less dence than watter in the first place.... also MOST non "armor/loadbearing" parts you can put in a ship are less dence or equaly as dence as watter "thats why an engine will float if attached to a single wood block"