Low Aspect Ratio (LAR) Keel Design
Low aspect ratio keels are very popular on cruising catamarans as they offer a good compromise between easy sailing and cost while also protecting the hull from possible grounding damage and usually add to the load carrying potential.
Unfortunately low aspect ratio keels are also both very inefficient in preventing leeway and in increasing pitching. So it is tempting to improve them by making them deeper and shorter. However deeper keels tends to negate one of the great advantages of catamarans - shallow draft. Short keels result in even more problems. Imagine drying out and have the crew go forward only for the bow to drop as the boat overbalances! Think of the ensuring damage to the boat, never mind to the crew if this happened on hard ground!!
No wonder that - as this photo of a well known design shows - many catamarans need props under the bows and often also under the sterns (a bit hard to fit them while drying out on a beach I would have thought!)
That is why I draw relatively long keels and accept the compromise between performance and practicality. See my article on LAR keels versus daggerboards on my Articles pages for more on this subject