Ometepe Island is similar to the rest of Nicaragua in some ways, but not all. One way is it similar is the chicken buses. They run at (fairly) regular intervals to every corner of the island, and are an inexpensive, although slow, way of getting around on Ometepe. Another similarity is hitchhiking. Although we never recommend doing this alone, especially at night, it is common enough, and most people with vehicles are more than happy to give you a ride across the island. However, Ometepe Island differs greatly from the mainland when it comes to taxis and shuttle buses. You will find they are relatively expensive, and charge rates significantly higher than on the mainland! They claim the rates are due to the cost of fuel on the island, however gas and diesel are only about 20% higher on Ometepe Island than on the mainland, and that just doesn't justify $20 and up for a ride across the island.
While many tourists, backpackers, and spelunkers do chose to rent a scooter, motorcycle or 4-wheeler, there needs to be some caution when doing so. There is no option for a conventional insurance policy like you would receive elsewhere for a vehicle rental. If you break it, you pay. If it gets stolen, you pay. If it (or you) falls off while you are driving it, you pay. It is very important to take highly detailed photos of the vehicle you are renting PRIOR to renting it. We also recommend taking a digital video (most have cell phones these days that can do it) of every square inch of the vehicle before leaving the rental station.
You should never leave valuables, or easily lost items on the vehicle while you are away from it. i.e., helmets, hats, shirts, bags, etc. You should never park the vehicle somewhere it is unattended overnight, this is an easy way to buy a new pair of mirrors!
Mechanical failures are about the only item that they will not charge you for. But that does not mean they won't try! Remember to always return the vehicle with a full tank of gas, or you will be charged! On our interactive map page you will find the three (3) main gas stations on the island. All charge basically the same price for gas. Navigating around the island is fairly simple. It is basically a figure 8 loop. Although, once you leave the pavement, you are on your own, as the majority of roads do not show up in the best of mapping programs (Google Maps and Apple Maps included). You should also be very careful when traveling off-pavement as there is always a cow, horse, dog, or person around every corner. In Nicaragua, if you hit a pedestrian, step one is you go to jail, and then they figure out the rest. And that can take years.... Keep in mind that includes stumbling drunks!
Driving at night, anywhere in Nicaragua, and not just on Ometepe Island, is never advised. Between horses running free, cows wandering everywhere, from dogs lounging on the warm pavement, to vehicles with no lights, you never know what is coming, and it takes all your senses to survive!
Now that we've scared you half to death, let's look at the positives!
You can rent bicycles, horses, scooters, motorcycles, 4-wheelers, and even 4x4 trucks on the island. Every place will offer you around the same prices. And prices are ALWAYS negotiable. They have two basic rates: A day rate (meaning you return it by 5pm), and a 24-hour rate. Motorcycles and scooters are typically the same price and the day rates can start pretty cheap (as low as US$5 in the off season), but are typically US$15-20. The overnight rates are higher; it seems to us mostly because of the hazards of night driving and petty thefts, but they will run anywhere from $15-25/day. Again, rates are ALWAYS negotiable, and if you are going to be here for a week or two you can get a really good deal.
There are some shady wheeler-dealer shops out there, but there are also plenty of honest, family run businesses that will be open, honest, up-front, and fair with you. It never hurts to shop around, and it always pays to ask questions! If you rent before you step foot on the island, you may find that you have over paid, and or have been misinformed. The "tourist" helpers at the port and the San Jorge taxi drivers don't always have accurate information. If you desire to reserve something in advance, I highly recommend doing it through an internet site.