Most galleasses had three masts with sails, in addition to rowers.
Their designers switched from an earlier layout that had many benches with short oars to fewer benches with 3 - 5 men per oar.
A large galleass needed 275 rowers and carried 75 marines.
The large crews required much water and food and the cramped conditions on board prompted galleasses to frequently visit a port.
Galleasses had fore- and aft-castles, where its heaviest cannons (firing up to 50 pound cannonballs) were placed.
Unlike regular galleys of the time, they also had a gun deck.
Here up to 20 light anti-personnel cannons were mounted, so that they could fire broadside.
Galleasses were slow ships.
They compensated by being capable of blasting smaller galleys out of the water.
When cannons became more reliable and could fire at longer ranges, galeasses quickly were outclassed by other ship types,
like the galleon, which could deliver devastating broadside salvos.
In the Mediterranean, where the waters are calmer than the ocean, galeasses remained in use during the 17th century CE.
War Matrix - Galleass
Age of Discovery 1480 CE - 1620 CE, Weapons and technology