Let’s start with the more-easily-calculable things, and get into the harder ones later.

Fuel

The most direct path of the great loop is, plus or minus, 6000 miles, but you’re going to stop in at marinas not right on the route, explore some rivers, bays, inlets, etc. So a more realistic round number is 6000 nm (nautical miles: 1nm = 1.15mile.)

The next part is pretty boat-dependent, since we’re calculating mileage efficiency. Every boat is different, and every captain will use their resources differently, but let’s try to give some rough criteria to work with. Boattest has been doing reviews of boats for decades and has fuel efficiency reports for many of them, so you may be able to get numbers for your boat right off there, or be able to find them on forums or other review sites. They’re really important numbers to know, since you’ll want to know what your range is for some of the longer legs of the loop. If you can’t find numbers for your boat, you’ll have to understand some basics and get some rough ideas.

Every boat has “efficiency humps” in their nm/gal vs. speed curve they need to be aware of and work around. Your first hump will be before “displacement speed” (also called “hull speed”). In a 40 ft boat, it’s a hair over 8 kts, in a 30 ft boat, it’s a hair over 7 kts. Stay under displacement speed for your best mileage. You’ll spend a significant portion of your loop doing displacement speed, because lots of the ICW and other inland waterways have speed limits, so this will be the overwhelming factor for your mileage. Here’s some really rough ideas for different types of boats, staying under hull speed:

• 30 ft gas sailboat: 4 nm/gal
• 30 ft gas cruiser: 1.75 nm/gal
• 40 ft diesel sailboat: 3 nm/gal
• 40 ft diesel trawler or catamaran: 2 nm/gal
• 40 ft diesel cruiser: 1.5 nm/gal
• 40 ft gas cruiser: 1.2 nm/gal
• 50 ft diesel cruiser: 1.0 nm/gal

In general, at hull speed, you should meet or exceed 1.0 nm/gal. Just be careful, and try to get numbers for your boat. You’d be shocked at how adding less than 1 kt of speed may nearly halve your fuel efficiency when you approach and pass through hull speed.

Cruisers/planing hull boats can go much faster than hull speed, when the boat steps up onto a “plane”, and rides somewhat on top of the water, doing 14+ kts. However, this comes with a huge decrease in efficiency:

• 30 ft gas cruiser: 1.2 nm/gal
• 40 ft diesel cruiser: 0.6 nm/gal
• 50 ft diesel cruiser: 0.4 nm/gal

Depending on your schedule on doing the loop, if your boat is capable of it, you may plane virtually none (outrunning a storm only), some (NJ coast, FL gulf crossing, etc.), or often. You’ll have to think about how much you like the journey vs. enjoying your destination to figure out how much your time is worth.

So, back to where we started, how much do you think you’ll travel at planing speed vs. displacement speed, and what nm/gal do you expect?

• 30 ft gas cruiser with a mix of fast/slow: 1.5 nm/gal -> 4000 gallons
• 40 ft diesel trawler that never planes: 2 nm/gal -> 3000 gallons
• 40 ft diesel cruiser with a mix of fast/slow: 1 nm/gal -> 6000 gallons
• 50 ft diesel cruiser mostly planing: 0.67 nm/gal -> 9000 gallons

If you pay a lot of attention to your fuel refills, you can use the Waterway Guide Fuel Report to help find the cheapest fuel coming up, and optimize your stops around it. At the time of writing, that means rarely paying much over 2$/gallon for diesel, or 2.50$/gallon for gas. But if you don’t pay attention, you can easily find yourself out of fuel and the only marina near you is selling what you need for 4-5$/gallon.

If you really have no idea yet, assume 1 nm/gal, paying 2.50$/gallon, and that’s 15,000$ for your fuel budget for the year. Maybe you’ll surprise yourself and save a bunch of money for the wine budget.

One last consideration is generator costs. If you don’t spend every night in a marina, you’ll be running your generator. If you save money on marinas by being on anchor, this could add up to a nontrivial sum of money, especially if you run your generator for hours on end or all night to keep the A/C going. Generators on loop boats often use between 0.5 and 1 gallon per hour, so if you run the A/C all night on a hot evening, you might end up burning through 10 gallons of fuel, which adds up real fast. Just something to keep in mind.

Moorage

People usually ask about the fuel prices first, but it’s the easiest to calculate, and also will likely end up being a lesser expense to moorage, so make sure to think deeply about moorage costs as well.

This expense hugely depends on what kind of boating you like to do. If you’re loners that enjoy a pretty sunset in a cove with no one else around, and you spend most of your time at anchor, then this expense will be very low. If you love wandering the docks with a drink in your hand looking for folks to chat with every night, then this expense will likely be very high. But no one can tell you how much this will cost, since it’s a very personal decision for how you want to spend your year aboard.

In general, in most populated areas of the loop, staying in a marina is going to cost you around 2$/ft/night, with 10-15$/night for power. If you stay in a super swanky marina, it may be 3$ or more per night — we’ve seen as high as 12$/ft/night in New York. In the middle of nowhere and/or swing seasons, we’ve paid under 1$/ft/night and 5$/night for power. Look around at all of the marina options in an area — it’s amazing how much variation in cost there may be for what feels like essentially identical services.

Some marinas will have the option of renting mooring buoys, which are a middle ground for many folks. Much less risk of any dragging in the event of winds/questionable bottom, easy tie up, no anchor cleanup, and no worrying about swinging into neighbors. Mooring buoys often only cost 20$ or so, with up to 40$ in really nice areas (where the marinas are usually 3$/ft, so still a substantial discount.)

Random rough numbers to give you an idea of a year on the loop (assuming 1.5$/ft/night + 10$/night power on average):

• 30 ft boat, 1/2 marina 1/2 anchor: $10000
• 40 ft boat, 3/4 marina 1/4 anchor: $19000
• 50 ft boat, 100% marina: $31000

Maintenance

This is where numbers start getting a lot fuzzier, and depends a lot on factors like your comfort repairing your own boat and condition of your vessel.

If you have a boat over around 10 years old, then you’re well into the curve of when you’re on a constant stream of things breaking. Most things on a boat that’s used fairly regularly have a short life span. Take your house, make all the parts low-volume semi-custom parts, then shake it around 24/7 for a year, and see how many things break. That’s boat life.

There’s obvious maintenance like changing the oil and fuel filters every 100-200 hours (which will be 5-10 times on your loop), which are nontrivial costs just for materials, much less man-hours of labor. But you will have other stuff break, at unfortunate times. Your raw water pump will probably have an issue, because they do that every 1000 hours or so on many boats. Your fresh water pump will probably have an issue, because they do that. Your toilet system will probably have an issue, because on most boats they’re often not really designed for full time liveaboard usage. How new is your bottom paint? That needs redoing every few years, especially with the miles you’re going to put on it. Touch a submerged log and bend a propeller and you’re coming out of the water for a few days and out several thousand dollars. The list goes on and on.

Marine technicians are, like any repair profession, often ~80$/hr or more, and if they need to come to you because you’re dead in the water stuck on anchor somewhere, there’s often heavy travel and emergency fees on top of that. Haul out fees are often 500$ or more, and then you need to find a hotel on top of that. Repairs are expensive and time consuming and never on your schedule.

For a really super rough number, and a boat starting the loop in reasonably good shape, make sure that you have 1000$/month tucked under a mattress for unplanned maintenance, plus a few thousand dollars over the course of your loop for planned maintenance (oil changes, paint, zincs, etc.) Let’s say $15000 for the year. You might get away super lucky with a fraction of that, or you might get screwed by a major breakage that costs a multiple of that. You’ll probably end up not too far off that number, though.

Food/Clothes/Toys/Misc.

The last category is actually the easiest. First time liveaboards tend to be very worried about additional costs over how they were living their life on land. Realistically, you spend about the same amount on these daily things as you did at home. If you like eating out, you’ll eat out a lot, and spend money there. If you go to a grocery store, it’s going to cost about the same as it did near your house. You’re probably going to go through, if anything, less clothes than on land, though maybe more opportunities for shopping might be a weak point for you to think about. But in general, take whatever you budget for these sorts of incidentals around home and match it for the loop. You won’t be far off what it turns out to be.

This question comes up virtually daily across the great loop forums, and unfortunately is one of the hardest to answer questions for prospective loopers. Because there are so many different constraints around budget, comfort, storage, speed, space, and more, the question is basically as open-ended as, “what car should I buy?” Basically, without providing more details, this is impossible to answer directly. So let’s try to help break down this problem.

Sailboat or Powerboat?

Let’s get the easy one out of the way. At the last poll, 9% of loopers owned a sailboat. If you want to do the loop on a sailboat, you’re either going to end up waiting for a lot of bridges to open coming up the ICW or you’re going to be doing a lot of ocean cruising out the outside, missing a bunch of small town fun. Then when you get to New York, you’ll have to pay someone to take your mast down and either ship it to you in several months somewhere on the Mississippi to put back up, or strap it down to the deck of your boat, taking up a bunch of super awkward space.

If you really love your sailboat, you absolutely can do the loop in one, and many do, every year. But it is highly advised to not do so, especially if you haven’t already done extensive liveaboard coastal cruising on one. There’s not much else to say here.

Physical Constraints

• Height/”Air Draft”
  • There is a fixed bridge on the Chicago Sanitary Ship Canal with a charted height of 19 feet 7 inches. On some days, depending on the “pool height” of the water source that feeds it, you may get up to an extra foot on top of that, and some days you may lose up to a foot from it. Basically, don’t rely on having much more than this, and if you’re close, be prepared to watch the pool height website like a hawk to find your day to pass through. If you can’t take down enough stuff once a year to clear this bridge, you have the wrong boat and will have a really awkward return journey back through the great lakes. There is absolutely no way around this bridge by water. If your boat is small enough, you may be able to be trucked around, but that process is usually incredibly expensive, and usually boats small enough to be trucked also can clear the height.
  • If you can clear 17 feet, you can take the optional (but neat) path through downtown Chicago instead of having to go for a small detour down the Calumet River.
  • If you can clear 15 feet 6 inches, you can take the entire Erie canal (if you so desire), letting you get from New York directly to Lake Erie without crossing into Canada. If you want/need to do a US-only loop, you will need to go this route, as the Welland Canal requires you to briefly clear Canadian customs to transit the locks.
• Draft – While there is no real “hard requirement”, here are some various things to consider:
  • 5 feet is the max draft to go through the Trent-Severn waterway (Canadian side of the great lakes), which many say is the highlight of their loop trip — you have to basically do a US-only loop with a draft greater than this.
  • The southern ~1/3 of the New Jersey ICW is only “controlled” to 4 feet of depth, though many skip this section entirely for several reasons, depth high among them.
  • Many of the poorer-maintained portions of the ICW have shoaling up to closer to 4 feet in sections.
  • The primary guidance from most experienced loopers is that, above 4 feet of draft, be very careful. Having to be that careful takes a lot of the fun out of things. So it’s doable, but try to avoid having to, if you can. Your blood pressure will thank you later.
• Beam
  • To cruise any of the Canadian canal systems, you must have a beam of 23 feet or less — this is your only hard requirement, and you can always do a US-only loop with more than that.
  • Most marinas will not have room for boats over 16-ish feet wide
  • The more beam you have, the more likelihood you will be on the end of a T-head, which is often rockier than inside the slips
  • In general, not a big deal. Plenty of smaller catamarans do the loop, and just do more anchoring out.
• Length
  • The smallest of the size concerns, from a hard-constraint standpoint.
  • To go through the Canadian locks, you must be under 90 feet.
  • To go through the US great lakes locks, you must be under 300 feet.
  • Just like with too much beam, larger boats struggle to find vacant marina slips, and you end up on a T-head a lot.

Range

There’s another hard constraint for the great loop: range you can go on a tank of fuel. Going up the coast, it’s not a big deal, but on the inland waterways, it suddenly gets a long way between fuel stops.

After COVID-19 has likely permanently knocked out Hoppies, your boat needs to be able to make it 252 miles between stops. If Hoppies is open again someday, then that number drops to 208 miles. But the number isn’t quite as straightforward as flat ocean cruising. The upper Mississippi tends to run an average of around 1 kt with you for 200 of those miles, but the last 50 miles up the Ohio and Tennessee rivers are usually 2-3 kts against you, so over the course of the leg, it roughly averages out. If you go really slowly and let the Mississippi slowly carry you down over several days, and then at your optimal efficiency head up the Ohio, you may get out slightly better than your usual fuel mileage, but don’t bet on it.

Smaller boats without enough native range tend to carry a bunch of jerry cans of fuel for this leg of the trip, or you can get larger fuel bladders that roll up and stow when you’re done with them.

Lastly, when you get to the Gulf coast of Florida, you’ll have a decision to make about whether to cross the shortest path across gulf between Carabelle and Tarpon Springs, or whether to slowly hop around the inside, going much further. If you have higher draft (~4.5 ft or more), you also HAVE to go the straight-across route. This route is 170 miles across open water, dozens of miles from land. If you have a slow boat, this is going to involve around-the-clock cruising. If you have a planing boat, and want to take advantage of that, make sure you have a planing range of the 170 miles to cross that gap.

Budget

For most boaters, for obvious reasons, budget is the #1 consideration. If you’re trying to budget for a boat as well as the year of expenses, read our post about budgeting for your loop year to help figure out a total budget.

If you are on a tight budget for your loop, be incredibly careful about spending too much of it on the boat. Boats break, more often than you want them to, at incredibly inconvenient and expensive times. Make sure to leave lots of room in your budget for repairs. The post linked above goes into more details about that.

By and large, if you think you’re getting “a deal” on a particular boat, be very wary. Buying a boat for weekend trips once in a while means you can sometimes get away with “a deal”. However, you’re buying a boat to live aboard for a year or more. You can bet pretty strongly that, over the course of putting over a thousand hours of runtime and a year+ of liveaboard wear on it, you’re going to pay back those “savings”, probably more so. Buy a boat with a strong maintenance history, you’ll thank yourself later, no matter how much of the work you can do yourself.

Next, boats depreciate, but differently than cars, for the most part. For a brand new boat, the first few years of ownership are like a luxury car — huge depreciation, often to 50% of the purchase price within 4 years or so of purchase. However, after maybe 10 years, the price often levels out and mostly stops depreciating, for another decade or so, until the equipment is so dated that a buyer is going to end up doing a major retrofit and/or expect an engine rebuild, at which point the prices start to drop again. Try to buy in that middle sweet spot of depreciation if you can, so if you want to sell your boat after your loop you don’t loose too much value.

How Big?

Okay okay I’ve made you read a bunch of other stuff, but you came here to be told whether you really want that 60 ft yacht or whether you should suck it up and buy that 32 ft Swift Trawler. Well, I have some bad news. I can’t tell you, but neither can anyone else. So the first point I want to get across is that no one can tell you what boat you should get for the loop, or even have particularly relevant information for you. Everyone will respond with their particular experience, which will be on everything from tiny boats crammed full of people and having a lovely time through to giant yachts with tons of room, where they still couldn’t find happiness on and wanted even more room, and everything in between.

This is an incredibly personal decision, and should be approached far more like buying a house than buying a vehicle. You’re going to be on this vessel, often times not even getting off it for days at a time, usually “stuck” with a spouse or other cohabitator in very close proximity. No matter how much you love/like each other, most people want the option to have some time and space to themselves once in a while.

The most useful one-liner answer to this question I’ve seen is, “as small as you can comfortably live on, and no smaller.” The smaller your boat is, the cheaper your loop gets (fuel economy and marinas), the more access to marinas you have, the easier it is to navigate in tight small marinas and narrow/shallow inland waterways, and likely the less both draft and air draft you have, opening up more options for routes and anchorages along the way.

The larger your boat is, the more room you have to comfortably live in, the more spare/redundant systems you probably have (two heads, two motors, more fuel/water capacity, etc.), a real shower, a desk to work at, a table to eat dinner at every day, a kitchen that’s not infuriatingly small with tiny semi-useless appliances, etc. Also, commensurately, the more it costs, from purchase through to every day of looping with it. So, it’s all a balance. Every boat is a compromise. The key is figuring out the right set of compromises for exactly your situation. Don’t let anyone else tell you what makes sense for you.

For some data points, looper boats tend to not be longer than around 45 feet, due to how much it limits your access to things, as well as that it’s hard to find boats much larger than that that fit the air and water draft requirements. That said, there’s plenty of bigger boats like Carver 560s that have made it around the loop, and their owners swear by them.

As a personal data point, our boat is a 42 foot flybridge aft cabin powerboat, which gives us the livable space of a larger boat, but in a smaller, uglier, taller, package. For a full-time working-remotely couple, we both agree that this is about as small as we would be comfortable living and working in side by side, all day, every day. But this is our situation. We both like our space. My wife likes to cook in a real kitchen with an oven. We like to spend weeks at a time on anchor, without having to come into a marina, and take real showers. I like the view and access of driving from a flybridge, and the maneuverability of twin engines. We had to modify the interior to build a custom desk for us to both work from every day. We added solar and a giant cell antenna to make sure we had reliable internet. Lots of decisions and tradeoffs. But here we are, and we’re happy with where we landed. Even with “only” a 42 foot boat, we still ended up on T-heads in around half of the marinas we stayed in coming up the ICW.

Many many many couples, even with kids, have done the loop on low-30-foot express cruiser boats, that literally just have a tiny inside living space+kitchen with 2 beds, and then a cockpit/driving area. And they will go on for hours about what a great time they had. That worked great for them. It would have immediately driven my wife and I completely batshit.

I’ve exchanged messages with a few couples who were ICW cruising in mid-50-footer boats, and got rid of their boats for larger ones, because, for their purposes, they couldn’t be comfortable enough living daily on a boat that small. Everyone has their standards/limits/desires, and every boat is a compromise.

The advice I give to everyone who asks this question is to go charter a boat in roughly the size range and style you are considering. Live on it for a week. That will give you an initial data set to work with. Then do it again with a different boat. Keep doing it until you start forming strong opinions about what to look for (and what to not get) in a boat. You’re going to be living on this thing for a year or more. Take the time to get it right, you will thank yourselves for it later.