User blog comment:Tardir/Red Crusaders Something.0/@comment-4608429-20130220235355/@comment-4608429-20130221172803

Well, the main purpose to Space Marine Naval Combat is to get the Marines to where they need to be, on a planet. Their ships are designed to withstand punishment and then get the Space Marines on the planet as quickly as possible. It has been observed that a Strike Cruiser can deploy a company of Space Marines, with support, within 20 minutes of arriving in orbit above a planet. That is not to say that their space ships lack in combat powers, just their more survivable and have shorter-ranged weapons and more boarding action capacity (i.e. boarding torpedoes, Teleport attacks, Caestus Assault Ram, ect.).

Ground Based actions varies from Chapter to Chapter, though one thing presides. They are small, rarely numbering above 100 Space Marines, so they are used in only the most crucial engagements. To make sure that they are where they need to be, the Space Marines use methods of transport that allow them to travel quickly, like Thunderhawk Gunships, Storm Ravens, and even deploying from space via Drop Pod. They also use shock and awe tactics, so are likely to deploy most if not all of their forces in one engagement to try and destroy the enemy in one blow, rather than drawing it out over several months. To make sure that they are in the right place at the right time they also require inelegance, which can come from a number of places, such as orbiting space ships, sensors, allied forces and Scouts (or the equivalent).