One of the reasons that many people buy catamarans is the perception that they are faster sailing boats. And there is no question that a catamaran CAN sail faster than a similar monohull–under some conditions. In some cases a LOT faster. No argument can be made again this. The question I was looking to answer for myself was if this ability to sail faster translated to faster times on longer passages. And the answer is, (surprise!) not at all clear.
Short of running a long series of long distance races, how could an answer to this question be generated? Well, on quiet night watch I come up with an approach to answer the question. I was going to set up a “virtual race.”
Our weather routing software takes data we enter about the performance of our boat under various wind directions and conditions, combines that with the forecast winds over the course of a passage, and generates a predicted optimum route and travel time. I realized that they have this data available for many other boats, so I can take our own well tested data for our Amel 53 foot Super Maramu and “race” a catamaran on a passage.
I picked our competition as a Lagoon 450. This is a boat that seems like one that an Amel 53 buyer might consider as an alternative. Similar amounts of space, similar costs if new. Not a boat renowned for its sailing performance, but certainly a very popular cruising boat. Certainly few people would expect an Amel to lead the pack of similar sized monohulls in a race, and the same could be said of other catamarans and the particular model of Lagoon I chose.
I decided that the race course was going to be a passage from Charleston, SC to Antigua, West Indies. This was about a 1400 nautical mile route that usually involves a variety of conditions, some downwind, some reaching, some hard on the wind. Also a passage I have done, so it had a feeling of reality to me.
I decided before doing any testing, that I was going to do this ONCE. No cherry picking results. I was going to use the results from the SPIRE weather model. I chose this because it tends to be the most accurate over open ocean areas, but it really wouldn’t matter which one I chose. There were going to be two different “races” run. One race would be sailing only, and one where using an engine was allowed. The rules are typical for what I use when I run our weather routing: If progress toward the destination is slower than 3 knots, then we motor straight on at 6 knots.
I would chose the day of departure at random, without evaluating the weather ahead of time. I used March 1, 2022. The results were, to me, very interesting.
First, if we allowed the use of the engine,
- Amel 53 Total Time: 10 days, 2 hours, with 3 days, with 15 hours of motoring. The total traveled distance was 1431 miles, for an average speed of 5.9 knots.
- Lagoon 450 Total Time: 9 days, 3 hours, and required 2 days, 8 hours of motoring and traveled 1440 miles, for an average speed of 6.6 knots.
With a full day faster passage, and an overall savings of 10% of total passage time, I can hear all the catamaran sailors out there cheering loudly for their horse in this race. Although when we look closer, we see that a 10% savings isn’t all that much, and it comes at a significant cost in fuel and engine hours. Still, a win, is a win, right? But wait! There is more…
Same everything… except this time NO motoring is allowed. I mean we have SAILboats, right? Everybody has to get to the destination under sail alone. Things now change—a lot.
- Lagoon 450 Total Time: 12 days, 3 hours to cover 1658 miles for an average speed of 5.7 knots.
- Amel 53 Total Time:12 days, 8 hours covering a distance of 1501 miles for an average speed of 5.1 knots.
Pretty darn close to a dead heat. Only 5 hours apart, minor differences in weather will make the difference in how arrives first.
What’s happened here? As expected, the catamaran is faster but there are directions that the twin-hulled boats just can’t go. When the direction they need to go is straight upwind, they need to cover a much longer distance than the well sailed monohull. It is just the nature of the beast, and the extra speed on a reach just can’t make up for that. On a route that was entirely upwind, the monohull would win this race handily… if nobody could use their engines.
If you are a partisan of one flavor of boat or another, you can pick nits with this simple analysis. With a little forethought I could have picked a route where one boat was dramatically favored over the other. For example, sailing from California to Hawaii, the cat would be the hands down favorite, and likely by a lot more than 10%. But for the return trip–almost all upwind–the order of finish would be completely reversed. I chose the route I did because I could not predict ahead of time which one would have the advantage.
For me, this was an exercise that basically proved with data something I had always told people when I was asked my opinion about getting a catamaran to go cruising: If you buy a cruising catamaran you are buying a motorsailor. There is nothing wrong with that, if that is what you want. Heaven knows there are a LOT of monohulls out there that are better motorsailors than they are sailboats. There are also a few catamarans that are great sailing boats in there own right, but these tend to be highly specialized machines, with high price tags. A Gunboat, an HH, some of the Catanas, are in this class.
In short, there are a lot of reasons good reasons that a catamaran makes sense for some people. But faster passages under sail are NOT one of them.
This is my opinion, and it’s worth exactly what you paid for it!
fetchinketch 