I just want to add that the designer of the Catris, Aldis Eglajs, also favors a smaller genoa-like sail instead of a big spi for fast multihulls.

His reasons are mainly the same ones pointed out by Rick, and the most important one is:

"The faster you go, the closer to the relative wind you sail increasing the advantage of the reacher/hooter against the spi."

That said, all the advantages of a smaller, flatter and more manageable sail follow - durability, practicity, ease of handling, price, etc.

The Catri 27 features a mainsail, a jib and a reacher (hooter, screacher - it's all the same). If you want a spi, that's fine, it is your boat after all, but the designer recomends a multi purpose genoa.

One way to make accepting the hooter concept less painful is to give a closer look to the evolution and use of the spinaker:

In the past all spinakers were symetric - now fast boats use asymetric spis and slow boats use symetrical ones.

In the past the aspect ratio of spinakers was very low and the sail very round - now they are thiner and flater. The faster boats use flatter and higher aspect ratio spis. The slower boats use full and round spis.

Conclusion: as the boat sails faster, the spinaker shape approaches that of the Hooter! It will not surprise me if the spinaker eventually "transforms" into a hooter in the faster boats.

Cheers