Hi Alexander - Interesting to read of your desire for more speed just as many on the trawler list are moaning about the cost of Diesel, which seems to be headed towards US$10. per US gallon. I predict that unless the cost of Diesel stabilizes, cats will return to their original form, one with a mast and two small engines. But then, I have always wondered why anyone would want to eliminate the mast, bridges notwithstanding. Regards, John "Seahorse" Dear friends My new power cat is a trawler cat Highland 35 from Fountaine Pajot weighting 6tn and powered with the maximum horse power engines according to the factory i.e Volvo D3 110hp at 3000 rpm. With these engines I get 19kn at WOT and 15-16kn cruising speed. Although is a semi planning boat I am thinking to replace the engines with the D3 160hp which have the same weight, the same dimensions but 50hp higher power at 4000rpm. How much increase in both maximum and cruising speed do you think that this change is going to obtain? Should I modify the propelers as well? Alex **************Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489