Society is about rules and every area has its own set. Maritime law is the set of rules set up to encourage basic etiquette on the water as well as establish penalties for disobeying the rules of the sea. However, a major difference between regular law and the maritime version is that the latter is a codified version of a long-standing set of etiquette that mariners have found works more often than not. While there are a number of modifications added in order to allow for modern technology, it is very likely that an ancient mariner would recognize the rules in play.
The laws have to allow first and foremost for the difference between freshwater, seawater, and the open seas. Laws involving water need to allow for the differences between environments as each has its own issues; after all, a boat driver has more control over the vehicle on a lake than in the sea and that loss of control has implications that need to be allowed. Recognition of lack of control is also represented in the right of way between different kinds of vessels, such as sailboats versus powered vessels; sailors respect the sea and how hard it is to control for the variables one may encounter while sailing.
There is also the issue that it is hard to tell precisely where one border ends and another starts even in the age of global positioning satellites. This is primarily a matter of jurisdiction between various branches of law enforcement as laws may change between jurisdictions over a number of different topics, and so part of the law has to address potential jurisdiction issues, especially when a vessel may constantly shift between different them. The literal fluidity between jurisdictions is a matter of treaty even between two counties and is a reality that makes enforcement of maritime law a nightmare for some officials.
Most of the laws are a matter of solidified courtesy. As the rules have been established as a matter of courtesy and most officials are willing to allow that; a group that makes its own rules also tends to enforce those rules making it easier on all parties involved. This means that the laws actually provide an element of firmness in an environment that may change at a moment’s notice; everyone knows where they stand. This creates a beautiful tradition that solidifies the community of sailors, and one that everyone has a voice in as they all have an interest in the laws, making it an interesting compromise between officials and civilians.