Learn your flight plan
Getting to the Marshall Islands is complicated to say the least. The only major US airline that lands in the country is United Airlines - and this is day of the week dependent. Everyone going through Hawaii will have to spend one night in Honolulu as the flight leaves before 7am. The Island Hopper route leaves Honolulu on Monday/Wednesday/Friday. Losing a day crossing the date line, you'll arrive on Tuesday/Thursday/Saturday, landing in the Marshalls on the way to Guam. On Monday/Wednesday/Friday (Marshalls Time), it comes back the other way. So what I'm trying to say is DO NOT MISS YOUR FLIGHT - or you'll be out another two days. This will also make your flight route look really weird and super expensive if you're dates are off. Follow the same plan for your return flight and you'll be good to go. While United is really your only main way into the country, you can test your luck on Air Marshall Islands and their short routes to some of the outer islands. But there is a reason the locals refer to them as Air Maybe.
Infrastructure is limited...like, really limited
While the Marshall Islands are comparable to the Maldives under the water, they are quite different in the accommodations department. There are a few hotels on Majuro, the capital and biggest city, but these are not all inclusive resorts by any stretch. Ebeye, on Kwajalein Atoll, is the seconds largest city, but tourism doesn't exist in this densely populated island adjacent to the US Army leased Kwajalein Island (where the airport is located). If you are lucky enough to know someone living on Kwajalein Island - where we lived for five years - you may be able stay with them after passing through all the Army background checks and getting official travel orders. Outside of these two main islands, the Marshall Islands are truly remote tropical island living conditions - most without power, plumbing, hotels, restaurants...anything you would associate with your typical vacation.
It's always good to be aware of the dangers that lurk in a foreign country. In this case, I'm mostly talking about loading up on sunscreen. The vast majority of the Marshall Islands lay within 10 degrees of the equator so, um, it's hot. Actually, it's not super hot as much of the sun radiates on you unlike anything you've ever felt before. I made it a point to always have sunscreen on my person between the hours of 10am-4pm, but better safe than sorry. You'll quickly learn about some of the not so common places that you'll need to protect like the tops of your ears, feet, and knees.
It's like riding a bike
Literally. Bike riding is the way on many of the populated islands in the Marshalls. The logistics of using vehicles rarely justifies the cost so it's either walking or biking - though Majuro does have some taxis for reasonable prices. On Kwajalein, the variety of custom bikes built by Americans with limited entertainment options is impressive. Be ever vigilant with your preventive maintenance though. Things rust like you've never seen in this tropical climate.
Get in the water early and often
By far, the most amazing part of this country comes from what lurks below the surface of the water. These world class coral reefs provide entire ecosystems of life for your viewing pleasure via snorkeling or SCUBA diving. Just like looking for nature in the woods, you might not see some of the best stuff if you don't go looking for it more than once or twice. Friends would always ask me how I was able to see so many amazing creatures for my videos. I would simply tell them that I go all the time and play the odds. Amazing creatures are out there waiting to have a once in a lifetime encounter with you. You just need to create the opportunities to see them.