my answer is a definite maybe.  it depends on two main factors -- 1) what is the rating on the receptacle - it should be rated for at least what you plan on upping the fuse to,  What size and how long is the wire from the fuse to the receptacle (the wire's "ampacity") ?  http://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity  use a chart like what is attached to determine if you can up the fuse.  Both items matter and the one with the lowest rating determines what fuse you can use..

Just a note about the "philosophy" of fuses and circuit breakers.

1. Let's begin with the Load. The size of the Load is fixed...let's say your pressure pump needs, oh, 13 amps of power at ship's 12 volts DC.
2. The next step in our logic is What kind of fixture the Load plugs in to, in this case apparently a cigarette lighter socket. What they call a "power charger" is merely a euphemism for a cigarette lighter socket, apparently one with just a bit more amperage capability than normal cigarette lighter socket. I'll bet that the same plug that fits into a so-called "power charger" will fit into a cigarette lighter socket. 
3. Reasoning backwards, now we begin to ask what's 'upstream' of the cigarette lighter socket. If we have a Load that requires, say, 13 amps, even though the cig socket can handle that, the important question is: Can the wiring to the socket handle that amperage? We ALWAYS select the wiring gauge based on the expected current draw from the Load...plus a sizable fudge factor.
4. The final step in our logic train is to select the size of the fuse (ie, circuit breaker). To fully appreciate this step, I am going to capitalize the following statement which I want every reader here to repeat out loud as they read it: THE PURPOSE OF A FUSE IS NOT TO PROTECT THE LOAD; THE PURPOSE OF A FUSE IS TO PROTECT THE BOAT. In other words, we ALWAYS select the fuse/circuit breaker size to protect the WIRING downstream of it, so that any single downstream wire cannot possibly be damaged if it were to incur a dead short to ground.

It's always good to review these principles. I hope this helps. 

Quote: "THE PURPOSE OF A FUSE IS NOT TO PROTECT THE LOAD; THE PURPOSE OF A FUSE IS TO PROTECT THE BOAT."

This is the golden rule..

There is one caveat to this and that is bilge, macerator, shower sumps or any pump that could become "stalled" as in a locked rotor event. In this case a fuse no larger than the manufacturer recommends must be used to protect the pump. I see this violated daily and also see the melted piles of plastic that go along with it.

This is why AUTO/OFF/MANUAL bilge switches are so handy. You can protect the feed wire from the battery, sized for minimal voltage drop, with a 15A fuse, but then insert the 4A etc. fuse the pump maker recommends in the face of the bilge switch. If the rotor stalls that fuse will trip, it is designed and sized to do that. A stalled rotor can easily catch a pump on fire before a fuse trips.