Two input speeds, knots.  From these two speed the results for five speeds are automatically calculated, these two speeds simply define the upper and lower limits of the speed range evaluated.  However, the user may override the automatic intermediary speeds & calculate five user specified speeds if desired.

For each speed, two iteration trim angles (upper and lower) are allowed as optional inputs.  Default values are used if iteration trim angle values are not specified.  These default values are normally satisfactory.

The calculative method needs to be specified.  Simply specify the value of "one" for Savitsky Long Form calculations and set to the value of "two" for Savitsky Short Form computations.

Hull characteristics

	Length Over All, LOA, feet (optional input)
	Length of Waterline, LWL, or Chine Length, feet
	Beam on Waterline, BWL, feet (optional input)
	Exit Angle, qAFT, of Aft Quarter Butt, an explanatory diagram is provided with this template.  This value is critical for proper operation and is therefore checked in this analysis.  For more details about this requirement refer to Pages 12 and 13 of Reference D.
	Deadrise angle, b, degrees, for vessels with variable deadrise, pages 93 and 94 of Reference A, suggests using the value at the stagnation line.   The stagnation line is shown in the first figure contained in the Reference portion of this spread sheet.
	Chine beam, b, feet, this is a critical value.  For vessels with variable deadrise, pages 93 and 94 of Reference A, suggests utilizing the value at the stagnation line.

Weight information

	Vessel light ship weight, pounds, without any people, luggage, personal gear, provisions, stores, fluids or cargo on board
	Weight margin on light ship, percent.  This is optional input, default values are provided.
	Cargo weight, pounds, can be left at zero default value.  This would include the weight of fish and ice if applicable.
	Number of crew and number of passengers, integer
	Additional equipment not included in light ship, pounds
	Duration of voyage, days, for calculating provisions and stores, can be set equal to zero
	Personal crew gear and passenger luggage, pounds, can be set to zero
	Portions of total fluid capacities to be applied in analysis, default values usually 2/3 are provided, however these values may be specified as inputs.
	Main propulsion engine tank capacity, gallons, and fuel type (diesel or gasoline).  This is a highly recommended input value, if provided an estimate of the vessel's range is automatically computed by this spreadsheet.
	Auxiliary fuel tank capacity, gallons, and fuel type (diesel or gasoline)
	Potable water tank capacity, gallons
	Sewage holding tank capacity, gallons
	Longitudinal center of gravity, feet, distance forward of transom to center of total weight present.  Initially this value may be estimated.  Weights may need to be rearranged change this value in order to get proper optimal planing boat performance.
	Vertical center of gravity, feet, distance above hull bottom to center of total weight present.  Initially this value may be estimated.  (Required for Savitsky Long Form calculations.)

Propulsion Plant Details:

	Installed brake horsepower
	Parasitic loads, horsepower, for pumps, generators etc.
	Continuous operating rpm, percentage, guideline values are given on the input sheet, simply select the applicable rpm percentage
	Propeller Shaft Angle, e, degrees (required only for Savitsky Long Form calculations for Savitsky Short Form computations set this equal to zero)
	Thrust moment arm, f, feet, perpendicular distance off shaft line to vessel's center of gravity.  (Required only for Savitsky Long Form calculations for Savitsky Short Form computations set this equal to zero.)
	Shafting efficiency, ratio, guideline values given, select appropriate value
	Propeller efficiency, ratio, a default value is present, however another value may be utilized for the calculations
	Vessel range required, nautical miles, optional input.  If this value is specified this spreadsheet will automatically determine if tanks provided are adequate to make the voyage distance specified by this input.

Properties of water (fresh or salt) that the vessel is operating in:

	mass density (Slugs/Ft3) and kinematic viscosity (Ft2/Sec)
	values are provided on the input sheet, simply select the applicable operating temperature and insert values associated with this operating temperature and the operational water type (FW or SW).  Intermediate values may be interpolated or Reference G may be consulted.

For each of the five input speeds the following is output for equilibrium conditions computed by this template:

	Trim Angle, degrees
	Drag Force, pounds
	Effective Horse Power
	Brake Horse Power
	Continuous Horsepower
	Estimated Range, based on tank capacity, nautical miles

Checks for porpoising instability

The input and output range of data is checked for applicability as per the limits of the hydrodynamic modeling data utilized.  For details see Reference A.

The total operational weight is automatically computed based on light ship margin selected, cargo present, persons aboard, voyage duration which affects stores and provisions, selected operational tank capacities and gear on board.

Supplemental values like the weight density of the water, displacement length ratio, estimated maximum possible displacement speed, speed length ratios, volumetric Froude numbers, equilibrium wetted length beam ratios, equilibrium drafts to keel and a lot of other intermediary values are also computed to obtain the equilibrium values for trim angles and drag forces.

Reference A: Daniel Savitsky, "Hydrodynamic Design of Planing Hulls," Marine Technology, October 1964 Issue, SNAME, Paramus, NJ 

Reference B: Daniel Savitsky and P. Ward Brown, "Procedures for Hydrodynamic Evaluation of Planing Hulls in Smooth and Rough Water," Marine Technology, October 1976 Issue, SNAME, Paramus, NJ

Reference C: Daniel Savitsky, "Chapter IV Planning Craft of Modern Ships and Craft," Naval Engineers Journal, Feb. 1985, Special Edition, American Society of Naval Engineers, Alexandra, VA

Reference D: Dave Gerr, Propeller Handbook, International Marine, 1989, Camden, Maine.

Reference E: Dave Gerr, Nature of Boats, International Marine, 1995, Camden, Maine.

Reference F: Joseph G. Koeble, Jr., "Performance Prediction Chapter," No. 120 Small Craft Engineering Resistance, Propulsion and Seakeeping, Reprinted Oct. 1975, University of Michigan, Ann Arbor, MI.

Reference G: J. B. Hadler, "Coefficients for International Towing Tank Conference 1957 Model-Ship Correlation Line," Report 1185, April 1958

Reference H: Alfred D. Isaacson, paper entitled "Sewage Pollution Control: A Guide for the Ship Owner & Design," SNAME Marine Technology, July 1977 issue.

Reference I: S9086-C6-STM-010/CH-096R1 "Naval Ships' Technical Manual Chapter 096 Weights & Stability," NAVSEA, 2 August 1996.