What is the comfort ratio of a sailing vessel?

If you’re looking into buying a bluewater sailboat or just evaluating options, you’ve likely come across the Comfort Ratio (CR). While it might not hold much weight for daysailers or racers, for cruisers, it’s a different story. A comfortable motion in heavy seas trumps an extra bit of speed or closer wind angles when you’re out on the ocean for weeks. In the sections ahead, we’ll dive deeper into how the CR is calculated, offering insights into the variables and coefficients that come into play.

What is the Comfort Ratio (CR) of a sailboat?

Created by renowned boat designer Ted Brewer, the CR gives an estimate of how comfortable passengers will be on a boat when it’s subjected to waves and swells. Ted Brewer introduced the Comfort Ratio as a somewhat informal measure, but it has since gained traction for its practicality. It offers a way to compare the motion comfort of vessels of similar type and size. The core idea is that the faster the motion of the boat, the more uncomfortable the passengers are likely to be.

In practice, this means that if you’re evaluating sailboats for long journeys or rough waters, the CR can be a helpful metric to consider. A higher CR indicates that the boat’s motion will be slower and potentially more comfortable for passengers in heavy seas, which can be crucial for maintaining the well-being and morale of everyone on board.

How do you calculate the Comfort Ratio of a sailboat?

The formula involves a mix of the boat’s displacement, waterline length (LWL), overall length (LOA), and beam (width at the widest point). Here’s the formula:

  • Displacement: The weight of the boat. Heavier boats typically have a higher CR because the extra weight dampens the boat’s movements in response to waves.
  • Waterline Length (LWL): The length of the boat where it sits on the water. A longer LWL usually leads to a lower CR, as the increased surface area can result in quicker, more abrupt movements.
  • Overall Length (LOA): The total length of the boat from bow to stern.
  • Beam: The width of the boat at its widest point. A wider beam can lead to a lower CR because it increases the boat’s waterplane area, making the boat’s motion quicker.

Each of these variables directly impacts the CR, determining how the boat will likely respond to waves and the subsequent comfort level for passengers on board. If you are currently looking at a specific boat type, you should be able to easily get all of the relevant info for the model from the website sailboatdata.com, most of the time you will already find the CR calculated on their website as well.

So let’s take our Fellowship 28 as an example:

The specifications

  • Displacement: 7,937 lbs (according to the technical specifications)
  • LWL: 23.62 ft
  • LOA: 28.22 ft
  • Beam: 8.69 ft

So the Fellowship 28 has a Comfort Ratio of around 27,34 which means it should have a slower motion and provide more comfort than a comparable vessel of this size.

Categories of the MCR

The Comfort Ratio can be effectively used as a tool to categorize different types of sailboats based on their anticipated comfort level and intended use. Below is a helpful guideline to interpret the Comfort Ratio of a sailboat:

  • Below 20: These are typically light racing boats, designed for speed rather than comfort. They are characterized by a tender motion, making them less ideal for long voyages or rough seas.
  • 20-30: Sailboats in this category are suitable as coastal cruisers. They offer moderate stability and are capable of handling varying sea conditions, making them a popular choice for those sailing near the shore.
  • 30-40: These are moderate bluewater cruisers, designed for open ocean sailing. A CR in this range indicates a boat that is stable and comfortable enough for extended voyages, balancing both performance and comfort.
  • 40-50: These heavy bluewater cruisers are built for long-haul ocean voyages. They are characterized by their robust build and enhanced stability, even in challenging sea conditions.
  • Above 50: Sailboats with a CR above 50 are extremely heavy bluewater cruisers. While they offer exceptional stability and comfort in rough seas, they might lack in performance, particularly in moderate winds.

Important things to consider when interpreting the CR value

Always compare similar types of boats

While the CR can be a vital tool, it’s essential to recognize its limitations. For very long boats of 45ft and more, or very short ones of 25ft and less, the CR can be distorted, with the calculations favoring longer boats and smaller beams. In these instances, the CR might not provide a true reflection of the comfort level onboard, and other factors and evaluations should be considered to gauge the boat’s performance and comfort in various conditions.

Take the Albin Vega 27 and the Bristol 27 for example. The CR classifies them as coastal cruisers because of their lower ratios (around 20 and 28 respectively). However, despite these ratings, both models have proven their worth in ocean crossings. They might not offer the luxury of a larger vessel like a 40 ft Hallberg Rassy, but they’re still up to the task for long-haul sailing.

It’s important to remember that the CR is most useful when comparing boats of a similar size. It isn’t a one-size-fits-all measure but is best used to highlight the comfort differences between comparable boats.

Taking wind, waves and the individual person into account

Understanding a boat’s comfort isn’t just about crunching numbers with the Comfort Ratio (CR). It’s also about how the boat handles wind and waves and how much motion the crew can comfortably tolerate. In calm waters, comfort is often about how much a boat heels – something the CR doesn’t directly measure. Boats with wider beams might be stable and comfortable when the water is flat but can feel less steady in a storm. On the flip side, narrower boats that tip easily might feel unstable in calm waters but ride the waves more smoothly when things get choppy. Evaluating a boat’s true comfort level also means looking at how it performs in different conditions and considering the crew’s comfort limits.

The Factor of Load

When assessing a boat’s Comfort Ratio (CR), there are often additional factors that can play a significant role in the actual comfort experienced on board but aren’t always immediately considered. One such crucial element is the boat’s load. A CR calculated for an empty boat can be significantly different when the vessel is fully loaded with provisions, gear, and additional equipment. These items add weight and can substantially alter the boat’s motion and, by extension, the CR. So, for a more realistic and personal assessment of comfort, it’s important to calculate the CR based on the typical load you anticipate the boat will carry.

Beyond the load, the location of the boat’s ballast is another often-overlooked factor that can influence comfort. It’s not a detail typically highlighted, but the closer passengers are to the boat’s ballast, the more comfort they tend to experience. The ballast, usually being the heaviest part of the boat, can have a dampening effect on the boat’s motion. It often acts as a fulcrum around which the boat pivots in rough conditions. The closer you are to this fulcrum, the less motion you’re likely to experience, leading to increased comfort. This detail, though subtle, can be significant when evaluating different boats and their respective comfort levels under various conditions.


What is a good comfort ratio?

There isn’t a universal “good” CR – it really comes down to your individual needs and sailing plans. Different types of sailing and varying conditions require different CRs.

For example, the CR for coastal cruising would be different from that for ocean voyaging. While there are general categories like racing boats, coastal cruisers, and bluewater cruisers to guide you, they should be viewed as initial markers, not definitive answers.

When it comes to ocean voyaging, it becomes even more nuanced. A CR can be a useful starting point but should not be the sole factor in your decision. It’s a helpful metric when comparing boats of similar type and size. But, remember, it’s about comparing “like with like” for the CR to offer meaningful insights.

In a nutshell, a CR isn’t an absolute measure. It should be used in conjunction with a detailed evaluation of the boat’s other features and your specific sailing conditions and preferences. Safety, performance, and individual needs should always take center stage in selecting the ideal boat.

What is the most comfortable sailboat according to the CR

According to data available on sailboatdata.com, the Eastwind 44 ranks highly in terms of comfort, as indicated by its Comfort Ratio (CR).

Is a CR of 28 better than 27?

It’s more complicated than a simple good or bad! The significance of an CR of 23.0 becomes clear only when compared with other boats. Analyzing this value in isolation isn’t going to provide a concrete answer. Especially when dealing with close numbers like these, a boat with a lower CR could potentially offer equal or even greater comfort due to various factors we’ve discussed earlier. Context and a detailed comparison are essential to make sense of CR values effectively.


The Comfort Ratio (CR) serves as a practical tool for gauging the potential comfort of a sailboat, but it’s not the be-all and end-all. Its strength lies in comparative analysis among boats of similar design and size. While it offers insights derived from variables like displacement and waterline length, it doesn’t capture the full spectrum of comfort on the water.

There are limitations to the CR, especially noticeable when applied to either very long or short boats. In these cases, a more holistic approach to assessing comfort, which includes real-world testing and consideration of other factors, becomes essential.

In sum, the CR is an aid, not a definitive metric. It provides useful insights but should be complemented by a sailor’s personal experience and the specific conditions in which the boat will be sailed. Every sailboat’s performance is a nuanced interplay between its design, the sea, and the sailor.

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