LOTS not to like here.
I assume this is a 12V
battery system. The wires carrying DC
power to that 1000W
inverter look to be GROSSLY undersized for carrying the 80+ Amps needed to generate 1000W of 220V
power. Ironically, this 12V connection is likely the most immediately dangerous thing here. 12V electricity is less dangerous to your body, but because of the MUCH higher
current flows is more likely to start fires.
The connections to the breaker should be in a box.
Connections like those in the DC feed to the inverter that are hidden inside
electrical tape are highly suspect. I am betting there are not nice, clean, waterproof crimps under there...
Wires should be supported at least every 0.5 meters, and always near their termination points.
Chafe protection is needed where those wires run over the sharp bulkhead corner.
I don't know enough about European
wiring codes to offer a definitive comment, but having a 220V
plug act as a distribution box seems VERY dicey to me. I wouldn't ever do that.
As a general comment, I don't think that household plugs are really suitable for permanently connected
equipment on a
boat. Sometimes unavoidable, but humidity, moisture, vibration, movement, etc. make them unreliable.
This is likely NOT a complete list. It's impossible from a
photo to determine that everything is just fine.
This is an amateur job by someone who didn't have a good idea about how to do things on a
boat. If there are other modifications to the
electrical system on this boat, it would be well worth having someone qualified have a detailed review of it.