Ailaros wrote:
It just struck me after reading a few other threads here. Who defends the ships of the imperial navy?

The first and foremost reason navies have had marines is to provide security on board ships, and to prevent boarding parties from capturing their vessel / capturing other vessels with boarding parties. The whole infantry that deploy from ships onto land thing is a relatively recent innovation.

But do space marines do this? I mean, there's only a relative handful of space marines, and they tend to get their attention eaten up by being special forces engaged in rapid strike assaults. Meanwhile there are, what, trillions of ships plying the void of space? There are no way there are enough marines to have a detatchment on all of them, much less being able to do both that and handle the security of their little fiefdoms at the same time.

Of course if a fleet attacks a space marine fleet en route to somewhere, or try to attack their fleet directly while some of the battle brothers are planetside then the space marines are going to be actual space marines, but what about everyone else? If I've got a trading vessel moving a billion tons of grain from an ag-world to a hive city, one of perhaps hundreds set to arrive that day, then who runs security on my ship? Surely the imperial navy doesn't have enough destroyers and cruisers to give everybody an escort either. And it sort of can't be the imperial guard because of the split (though I could possibly see this in the form of a tiny detachment on each ship).

So what's the proverbial PDF of space-faring vessels?

 ArbitorIan wrote:
Could we not define marines as soldiers that primary fight FROM ships?

In this case, Space Marines certainly fit the bill - travelling to the conflict shipboard and then performing rapid strikes from the ship via drop pod or thunderhawk. Rarely would they set up a base.

Technically, I guess you could therefore class IG as 'marines' by this definition.

 Ailaros wrote:

 ArbitorIan wrote:
Could we not define marines as soldiers that primary fight FROM ships?

In this case, Space Marines certainly fit the bill - travelling to the conflict shipboard and then performing rapid strikes from the ship via drop pod or thunderhawk. Rarely would they set up a base.

Technically, I guess you could therefore class IG as 'marines' by this definition.

Exactly.

And it's not to say that a ship full of imperial guardsmen in transit somewhere wouldn't defend itself, of course, but it seems a bit dubious, fluffiwse, that there would be regiments of guardsmen on battleships in case they got boarded.

Taffy17 wrote:How important is ship protection when your probably spending most of the journey in the warp?

That's sort of like asking how important ship protection is when you're spending most of the journey at sea.

On the one hand, not all of the journey happens in the deep void. They have to come out of the warp at some point and are thereafter subject to the threat of "costal" raiders (or worse, some DE waiting around until right after you drop into realspace and then attacking). And then there's all that time that they're "docked" which I assume usually means they're still hanging out in orbit and may or may not be adequately protected by other naval vessels or ground-based weapons. Plus, there's security you have to provide on the ship as well. A bunch of sailors get drunk and start a brawl on the ship, someone has to come in and break everything up / send people to the brig.

And the warp isn't exactly perfectly safe either. Demons could easily find their way on board, for example, and there are CSM fleets that operate in the warp as well, among other dangers.

Sienisoturi wrote:The uplifting primer mentions that the ships themselves are defended against boarding actions by on board armsmen, that are most likely very similar to imperial guard, and of course any on board troops will help the defences also.

I guess they could be something like arbites, but are they actually arbites?

Taffy17 wrote:
originally they were probably just called marines because GW thought it sounded cool.

The primer does not mention anything about arbites, but I could imagine them being similar to less elite elysians.

 Psienesis wrote:
The USMC is still a sub-division of the USN.

 Psienesis wrote:
Because naval combat is a non-issue in today's world.