Horsepower Calculation

[JerryF]

Jacques,<BR><BR>Would you please list the factors used in calculating recommended hp values for a given hull. I know that transom width is a factor, but what else is considered. Are LWL, max beam, displacement, or hull form (for example) used? Is there more than one standard for this (USCG, ABYC, others)?. I am only looking for a general idea, not the exact formula.<BR><BR>thanks

[jacquesmm]

The USCG recommendations are explained in 10+ pages booklet. We use a spreadsheet to check. The figures on our web site are mostly based on my opinion but always below that max. HP.<BR><IMG SRC="images/forum/icons/icon_wink.gif"> <BR>The main factors are boat length and transom width. <BR>Hull form, boat and steering type are also considered. <BR>This makes sense for a normal boat but imagine that you design something 10´ wide by 10´ long with a slight vee, the formula gives max. 110 HP!<BR><IMG SRC="images/forum/icons/icon24.gif"> <BR>We are currently designing a boat that is 20´ long and will go 30+mph with 30HP but the USCG formula produces max. 230 HP!!!<BR><IMG SRC="images/forum/icons/icon_razz.gif"> <BR>USCG rules are not a boat design tool and do not replace experience.<BR> <IMG SRC="images/forum/icons/icon_eek.gif"> <BR><BR>A good opportunity to use those nice little pictures . . . <IMG SRC="images/forum/icons/icon_biggrin.gif"> <BR><BR><font size=1>[ This message was edited by: jacquesmm on 23-10-2002 15:53 ]</font>