Speeds are dependent on the type of catamaran - dinghies and bigger cats with dagger boards will make much higher speeds than a cruising cat. So you make your choice - performance or comfort. And of course how many crew you want to have on board. Not really very different from the choice of a racing or cruising monohull. Just don't assume that all cats are really fast.
On the
Prout vs Solaris page I have produced a small table comparing some of the cruising cats we considered - Prout Elite, Solaris Sunrise 36, Broadblue 385, Lagoon 380 and then, as an outlier to show the difference in figures for a fast cat - a Dazcat 10. This lists length, displacement and performance indicators. However, here I'll just provide a simple comparison - length vs Kelsall Sailing Performance - a much used calculation from the work of Derek Kelsall, legendary designer of multihulls who died in 2023 -
Yachts & Yachting article. KSP takes into consideration LWL, Sail Area and Displacement.
| Make/Model |
Prout 37 Elite |
Lagoon 38 |
Broadblue 385 |
Solaris Sunrise 36 |
Dazcat 10M |
| LOA ft |
37.00 |
38.00 |
38.65 |
36.00 |
32.70 |
| LWL ft |
34.00 |
36.00 |
35.24 |
34.00 |
31.80 |
| KSP kn |
5.93 |
6.52 |
7.09 |
7.10 |
10.05 |
There are more figures on the
Prout vs Solaris Sunrise page. The figures come from
Multihull Dynamics website. We were surprised to see these figures - perhaps they should be taken with a pinch of salt ! I think what does emerge is that the cruising cats of a similar size length have pretty similar performance whereas the Dazcat which is shorter is a different beast and significantly faster. Probably the issues below create a greater disparity in performance than the build figures might suggest :
- Loaded weight
- Hull and props - condition, type ...
- Sea conditions
Performance Off the Wind
This is where a catamaran really enjoys life. Downwind with a spinnaker or cruising chute - the beam means that the setting of sails and the downwind ride are much easier than on a mono. Either straight downwind (remember all those rolly time you've had with a mono ?) or on a reach.
You can expect a cruising cat to be easier to manage (far less chance of broaching in a seaway) and typically you can expect 25% better speed than a comparable length of monohull. In a flat sea you could even be looking at a 50% increase from say 6 knots to 9 knots. It is vital to have a clean hull - the power generated by a heavy monohull will get them through even if they're a bit barnacled - far less true of the lighter hulls of the cat. Nor do cats tolerate being loaded heavily in the way that heavy monohulls will - I shall not be carrying the sewing machine on board any longer !
Rule of thumb says a cruising cat will be 20-30% faster off the wind than a comparable cruising monohull of the same waterline length. Remember that the shape of a cat means that you will get a longer waterline length for the same LOA (length overall) especially if making the comparison with classic yachts with lovely cut-away sterns and swooping bows. Our 41 ft monohull had a waterline length (before heeling) of 32 ft. Our Solaris Sunrise has an LOA of 36ft and a LWL (waterline length) of 35ft.
Too Much Sail One of the odd things for an ex-monohull sailor to remember is that if your cat becomes over-powered you should bear away to reduce rig strain instead of luffing up ! All a bit odd to start with but the good news is that virtually no cruising catamarans - certainly of the type discussed on this web site - Solaris, Prout, Broadblue, Catalac etc - have ever capsized. But then I'd say that's true of the vast majority of solidly built monohulls too. We won't discuss the Fastnet of 1979 - not only were those boats racing but the sea conditions were quite extraodinary.
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Beating
Beating to windward is not the catamaran's favourite point of sailing. So expect to sail further off the wind. Doing so can increase your speed through the water and may make your VMG (velocity made good) better than trying to sail as you would in a monohull. Pinching is not a good idea - let the girl go !
We still passage-plan at 6 knots as we did with our 41ft monohull. If we had a downwind passage as we once did from Dartmouth to Plymouth in an easterly we'd exect the Solaris to be faster, more comfortable and less worrying - a rising wind when you're goose-winging is always a concern.
Had we been going the other way - into the easterly - I'd prefer a monohull. But if you're lucky enough to be cruising and time is largely your own the better decision would be to go for a pleasant walk or do some boat jobs.
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Motor Sailing
Many catamaran sailors will stick an engine on while sailing to improve windward performance. Because the noise and vibration is generally less on a cat (dependent on what type of engine(s) you have) this can be far less intrusive than on many monos.
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Gear Weight
Cats are generally much lighter-weight than a comparable monohull - no proper keels for starters. So all the sailing gear tends to be much lighter-weight and easier to handle - one of the advantages we were looking for - even though we knew a cat couldn't possibly perform the way a traditional monohull would - especially to windward.
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