A concept drawing of the foiling monohull to compete in the next America's Cup

An American sailing expert has described the planned 75-foot monohulls to be used at the America's Cup as looking "like some kind of space alien".

Brian Hancock, writing for the website Sailing Anarchy, doesn't appear all that impressed with the design decisions for the 36th America's Cup.

An experienced offshore sailor, Hancock even said the yachts "looked like a dog peeing".

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"The hull is pretty ordinary but it's the strange appendages that stick out each side to allow the boat to foil that has many people atwitter," Hancock wrote.

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"Frankly I am not that impressed. I have always gone with the notion that pretty boats sail fast. This design is anything but pretty.

"It looks like some kind of space alien. Someone in the comments section on YouTube said it looked like a dog peeing.

"At the risk of challenging the design team, who I know are infinitely smarter than me, I am going to say that I don't think that this is going to work very well."

Hancock said he believes the boats will take a long time to foil because of their weight, and isn't convinced that tacking will be any faster.

"Maybe I am wrong but it seems to me that this design is going to have the same problem that the multihulls had. Tacking is slow and the boats are going to drop off their foils.

"I am guessing that it's going to take a 75-foot monohull much longer to get back on its foils than it did the AC45's.

"My bet is that their best option will be to bang a corner, stay on the foils for as long as possible, work on boat speed and hope that you have chosen the right corner."