I563 Design data : interpretation
Posted: Tue Sep 07, 2021 12:18 pm
G'day all, hope you are not holed up too much! (as i have)
Been studying Design data to compare different boats.
Studied it because i'm interested in where the safety envelope may be for coastal cruising, boat performance and comfort (or not)
Found the Investigator 563 made it onto the world-stage within the "Sailboat data" website!
https://sailboatdata.com/sailboat/investigator-563
Here are some figures with interpretations i got from the internet (notebook form at the moment). Most are good (but the capsize screening seems a bit contradictory.)
SA/D = sail area/displacement ratio. I563 = 21 : "good sailing performance"
B/D = ballast/displacement ratio. (righting moment) I563 = 46 : "heavy bluewater boat" (high righting moment)
D/L = displacement/length ration. I563 = 165 : "Moderate displacement"
Comfort ratio. I563 = 11.4 : "Lightweight racer" (this is where it doesn't sound quite right to me, for its size it seems fairly comfortable..but then they're comparing it to large yachts)
Capsize screening. (Bought in for racing yachts after fastnet disaster) below 2 is good. I563 = 2.33 (could be prone to capsize offshore). This is understandable due to its very short length)
I was interested in studying this design stuff to quantify to good feeling i have of the design for coastal cruising (while picking the weather and wind direction etc). I have taken "Teria" upto what i think are near her upper limits so far (beating into >30 knots with sharp >2m waves of a headland, which got so uncomfortable/ plain scary! and required a turn-tail downwind run back to shelter! never looked like capsizing. perhaps smaller headsail and extra reef in mainsail could fix this and make an I563 operate above 30 knots)
This sailboatdata is also very useful if you are thinking of a larger cruising boat design, how seaworthy it is and whether its an overweight slug vs good performer. (So far i've found Tophat25's, H28's tick the good coastal cruising boxes plus sail well).
Been studying Design data to compare different boats.
Studied it because i'm interested in where the safety envelope may be for coastal cruising, boat performance and comfort (or not)
Found the Investigator 563 made it onto the world-stage within the "Sailboat data" website!
https://sailboatdata.com/sailboat/investigator-563
Here are some figures with interpretations i got from the internet (notebook form at the moment). Most are good (but the capsize screening seems a bit contradictory.)
SA/D = sail area/displacement ratio. I563 = 21 : "good sailing performance"
B/D = ballast/displacement ratio. (righting moment) I563 = 46 : "heavy bluewater boat" (high righting moment)
D/L = displacement/length ration. I563 = 165 : "Moderate displacement"
Comfort ratio. I563 = 11.4 : "Lightweight racer" (this is where it doesn't sound quite right to me, for its size it seems fairly comfortable..but then they're comparing it to large yachts)
Capsize screening. (Bought in for racing yachts after fastnet disaster) below 2 is good. I563 = 2.33 (could be prone to capsize offshore). This is understandable due to its very short length)
I was interested in studying this design stuff to quantify to good feeling i have of the design for coastal cruising (while picking the weather and wind direction etc). I have taken "Teria" upto what i think are near her upper limits so far (beating into >30 knots with sharp >2m waves of a headland, which got so uncomfortable/ plain scary! and required a turn-tail downwind run back to shelter! never looked like capsizing. perhaps smaller headsail and extra reef in mainsail could fix this and make an I563 operate above 30 knots)
This sailboatdata is also very useful if you are thinking of a larger cruising boat design, how seaworthy it is and whether its an overweight slug vs good performer. (So far i've found Tophat25's, H28's tick the good coastal cruising boxes plus sail well).