Ship crews can disembark to fight as infantry, they have the following statistics.

Suihei (Sailors)
Unarmoured men armed with small melee weapons and short bows
Details:  Irr/UI: SA, Bow [Mrn]      
Req: N/A Mst: N/A Mnt: See below
Mrl: 2 Mv: 2      
Mle: 2 Reach: 0 Chg: +0  
Msl: 3 Rng: 1/2/3      
Def: 10 Coh: 2 Hits: See below  
AP: 0 SP: 0      
Notes: Move and attack when disembarking    
  Full strength for Boarding      
Suihei only have to be maintained if they are operating away from their ships (assuming the ships are being maintained). They require 0.5 GB/hit to maintain.
The number of hits a Suihei unit has depends on the class of the ship: Light ship crews have 1 Hit, Medium ship crews have 2, and Large ship crews have 3.