Sign on ferry

Found this bad example while researching on signage. This sign was found on a ferry in Ireland crossing the shannon.

There are three main areas which form what we understand as semiotics; the signs themselves, the way they are organised into systems and the context in which they appear. The first interpretation of this sign was a hand holding a knife. The colour red represent warn, as well as the explosion shape resemble the action like stab, hit, grab, bang etc,. Therefore, this could be a warning sign of people being stab. On the other hand, it could be a sign to remind people to hold tight to the handles (easy to fall down). This sign have not got any words for explanation which makes it harder to understand.