Bringing any type of drug into or out of a country is illegal in most places, so don’t bring them with you when traveling (or at least make sure it’s legal first).
Driving under influence of drugs is also illegal in most places, and for good reason. Do not drive under influence to avoid any problems.
Many places do not allow the use of drugs in public, even when they are legalized for recreational use. Make sure it is legal before lighting a joint in a public place.
In contrast to what most people think, Hawaii is still not one of the states that fully legalized marijuana.
Since the year 2000, cannabis is currently legal only for medical use. At first, qualified patients could only grow the plant themselves, and were not given any dispensaries to buy from. This later changed in July of 2015, when the state allowed for dispensaries to finally open in Hawaii, and offer various cannabis products to those with a marijuana medical card.
While marijuana is still not completely legalized, it is pretty common to see people using the derived products recreationally, sometimes even in public. Nevertheless, we do not advise any travelers to carelessly ignore the law and follow the local tradition, because the locals probably know better what they are getting themselves into, and the last thing you want on your trip is to have issues with the law enforcement of another state.
From the beginning of 2018, even patients that attain the marijuana medical card in another state will be able to use the dispensaries in Hawaii to purchase your favorite strains of product for medical use.