Club
Certificate
2023

Boat

UNDERWOOD

ESP-5122_C

RFEV
c/ Gamazo sn
39004 Santander – España
crucero@rfev.es
Rated boat velocities in knots
Wind Velocity6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Beat Angles44.4°42.9°41.8°41.4°40.6°40.0°39.9°
Beat VMG2.473.063.473.794.064.244.36
52°3.824.645.215.635.926.106.25
60°4.054.875.455.846.096.266.44
75°4.205.045.656.036.266.436.66
90°4.505.436.036.346.516.606.75
110°4.595.566.146.466.706.907.24
120°4.455.426.076.426.686.917.39
135°4.035.015.776.236.536.787.29
150°3.474.445.245.876.276.547.00
Run VMG3.003.854.575.195.756.166.67
Gybe Angles147.5°151.4°155.0°161.0°173.6°178.4°179.0°

APH: 694.0

CDL: 6.262

GPH: 785.6

CertNo: 512201

BOAT
ClassDUFOUR 31DesignerM. DUFOURBuilderTAYLORAge date02/1978Series date01/1975Offset fileE120.OFFData fileE5122_C
HULL
Length Overall9.320 mMaximum Beam3.288 mDraft1.819 mDisplacement5,098 kgDLR12.4732IMS DivisionCruiser/RacerDynamic Allowance0.720%Age Allowance0.487%
PROPELLER
InstallationShaft non exposedTypeSolid 3 bladesDiameter0.380m
CREW
Maximum weight350 kgMinimum weight263 kg * when appliedNon Manual PowerNoCrew Arm Extension
SAIL AREAS (m²)
MeasuredRatedMainsail18.2518.55Headsail Luffed19.1819.18Headsail FlyingSymmetric57.4057.40Asymmetric
STORM SAIL AREAS (m²)
Trysail5.26Storm Jib6.85Heavy Weather Jib18.49
SAIL LIMITS
Headsails1 * Woven polyester sails  Spinnakers4
STABILITY
Righting MomentN/AStability IndexN/A
The owner and any other person in charge is responsible that boat is complying with her certificate in accordance with RRS 78.1 and ORC Rule 304.
ORC Ref  03510002ED6Issued on 22/03/2023Valid until 31/12/2023
VPP ver: 2023 1.01 | © ORC | www.orc.org

Club
Certificate
2023

Boat

UNDERWOOD

ESP-5122_C

RFEV
c/ Gamazo sn
39004 Santander – España
crucero@rfev.es
Time Allowances in secs/NM
Wind Velocity6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Beat VMG1459.01176.41036.7949.1887.1848.2825.4
52°943.3775.8691.2639.4608.6590.5575.9
60°889.3739.4660.7616.0590.7574.9559.3
75°856.4713.6636.9597.3575.1560.2540.6
90°800.8662.8597.4568.3552.9545.3533.1
110°783.9647.9586.3557.2537.6521.6497.1
120°809.0663.6593.1560.4539.3521.1487.4
135°893.2718.6624.1577.5551.3531.2493.8
150°1037.7810.1686.7613.2574.5550.7514.0
Run VMG1198.2934.6788.3693.1626.5584.7539.7
Selected Courses
Windward / Leeward1328.61055.5912.5821.1756.8716.5682.5
All purpose1021.4825.3724.7666.6629.6605.8580.2
Single Number Scoring Options
CourseTime On
Distance		Time On
Time
Windward / Leeward857.90.6994
All purpose694.00.8645
 
Custom scoring options for Australia
Scoring OptionTime On
Distance		Time On
Time
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Custom scoring options for Austria
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Brazil
Scoring OptionTime On
Time
Upwind "bolina"0.5848
Downwind "popa"0.7828
70% up, 30% down "Ilhabela"0.6328
30% up, 70% down "Ilhabela-inverso"0.7106
Custom scoring options for Bulgaria
Scoring OptionTime On
Distance		Time On
Time
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Predominantly Upwind765.10.7842
Predominantly Downwind690.50.8690
Custom scoring options for Canada
Scoring OptionTime On
Distance		Time On
Time
Triple Number All Purpose Low923.40.6498
Triple Number All Purpose Medium689.90.8697
Triple Number All Purpose High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Predominantly Upwind765.10.7842
Predominantly Downwind690.50.8690
Predominantly Upwind Low1065.40.5632
Predominantly Upwind Medium802.70.7474
Predominantly Upwind High705.50.8504
Predominantly Downwind Low970.00.6185
Predominantly Downwind Medium671.40.8936
Predominantly Downwind High563.91.0639
Chicago-Mac Upwind0.7654
Chicago-Mac All Purpose0.8049
Chicago-Mac Downwind0.8528
Bayview-Mac Cove Island0.7365
Bayview-Mac Shore0.7381
Scoring OptionTime On
Distance		Time On
Time
Predominantly Reaching652.60.9194
Predominantly Reaching Low821.50.7304
Predominantly Reaching Medium644.70.9306
Predominantly Reaching High564.61.0626
5-Band
Windward/Leeward		Time On
Distance		Time On
Time
5-Band Low1307.60.4589
5-Band Low / Medium1083.50.5538
5-Band Medium836.30.7175
5-Band Medium / High726.40.8260
5-Band High688.40.8716
Custom scoring options for Cyprus
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Denmark
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Spain
Scoring OptionTime On
Distance
Coastal/Long Distance757.0
Triple Number Coastal/Long Distance Low923.4
Triple Number Coastal/Long Distance Medium689.9
Triple Number Coastal/Long Distance High602.2
Triple Number Windward/Leeward Low1192.1
Triple Number Windward/Leeward Medium855.1
Triple Number Windward/Leeward High713.9
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Estonia
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Finland
Scoring OptionTime On
Distance		Time On
Time
FinRating (Coastal/Long Distance)757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for France
Scoring OptionTime On
Distance		Time On
Time
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Custom scoring options for Germany
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.6498
Triple Number Coastal/Long Distance Medium0.8697
Triple Number Coastal/Long Distance High0.9964
Triple Number Windward/Leeward Low0.5033
Triple Number Windward/Leeward Medium0.7017
Triple Number Windward/Leeward High0.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Greece
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Hungary
Scoring OptionTime On
Distance		Time On
Time
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Custom scoring options for Israel
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Japan
Scoring OptionTime On
Distance		Time On
Time
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Korea
Scoring OptionTime On
Distance
Triple Number Coastal/Long Distance Low923.4
Triple Number Coastal/Long Distance Medium689.9
Triple Number Coastal/Long Distance High602.2
Triple Number Windward/Leeward Low1192.1
Triple Number Windward/Leeward Medium855.1
Triple Number Windward/Leeward High713.9
Predominantly Upwind765.1
Predominantly Downwind690.5
Predominantly Reaching665.6
Custom scoring options for Lithuania
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Netherlands
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.6498
Triple Number Coastal/Long Distance Medium0.8697
Triple Number Coastal/Long Distance High0.9964
Triple Number Windward/Leeward Low0.5033
Triple Number Windward/Leeward Medium0.7017
Triple Number Windward/Leeward High0.8405
Coastal/Long Distance0.7927
Predominantly Upwind0.7842
Predominantly Downwind0.8690
Custom scoring options for Norway
Scoring OptionTime On
Time
Tretall Distanseseilas Lite vind0.6498
Tretall Distanseseilas Mellomvind0.8697
Tretall Distanseseilas Mye vind0.9964
Tretall Pølsebane Lite vind0.5033
Tretall Pølsebane Mellomvind0.7017
Tretall Pølsebane Mye vind0.8405
Distanseseilas ett tall (OSN 8-16kn)0.7927
Distanseseilas ett tall (APH 6-20kn)0.8645
Enkeltall Motvind0.7842
Enkeltall Medvind0.8690
Custom scoring options for Portugal
Scoring OptionTime On
Distance		Time On
Time
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Coastal/Long Distance757.00.7927
Custom scoring options for Russia
Scoring OptionTime On
Distance		Time On
Time
Predominantly Upwind765.10.7842
Predominantly Downwind690.50.8690
Custom scoring options for South Africa
Scoring OptionTime On
Distance		Time On
Time
Cape Doctor Inshore692.70.8661
Cape Doctor Coastal587.91.0206
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Custom scoring options for Slovenia
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.6498
Triple Number Coastal/Long Distance Medium0.8697
Triple Number Coastal/Long Distance High0.9964
Triple Number Windward/Leeward Low0.5033
Triple Number Windward/Leeward Medium0.7017
Triple Number Windward/Leeward High0.8405
Custom scoring options for Switzerland
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.6498
Triple Number Coastal/Long Distance Medium0.8697
Triple Number Coastal/Long Distance High0.9964
Triple Number Windward/Leeward Low0.5033
Triple Number Windward/Leeward Medium0.7017
Triple Number Windward/Leeward High0.8405
Custom scoring options for Sweden
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Predominantly Upwind765.10.7842
Predominantly Downwind690.50.8690
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for Ukraine
Scoring OptionTime On
Distance		Time On
Time
Coastal/Long Distance757.00.7927
Triple Number Coastal/Long Distance Low923.40.6498
Triple Number Coastal/Long Distance Medium689.90.8697
Triple Number Coastal/Long Distance High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Performance Curve6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt
Coastal/Long Distance1315.6988.2818.5714.0653.1611.7556.2
Custom scoring options for United States of America
Scoring OptionTime On
Distance		Time On
Time
Triple Number All Purpose Low923.40.6498
Triple Number All Purpose Medium689.90.8697
Triple Number All Purpose High602.20.9964
Triple Number Windward/Leeward Low1192.10.5033
Triple Number Windward/Leeward Medium855.10.7017
Triple Number Windward/Leeward High713.90.8405
Predominantly Upwind765.10.7842
Predominantly Downwind690.50.8690
Predominantly Upwind Low1065.40.5632
Predominantly Upwind Medium802.70.7474
Predominantly Upwind High705.50.8504
Predominantly Downwind Low970.00.6185
Predominantly Downwind Medium671.40.8936
Predominantly Downwind High563.91.0639
Chicago-Mac Upwind0.7654
Chicago-Mac All Purpose0.8049
Chicago-Mac Downwind0.8528
Bayview-Mac Cove Island0.7365
Bayview-Mac Shore0.7381
Harvest Moon Regatta593.41.0111
Scoring OptionTime On
Distance		Time On
Time
San Francisco Bay Heavy705.50.8504
San Francisco Bay Medium851.20.7049
Predominantly Reaching652.60.9194
Predominantly Reaching Low821.50.7304
Predominantly Reaching Medium644.70.9306
Predominantly Reaching High564.61.0626
Windward/Leeward 60-40 Low1217.20.4929
Windward/Leeward 60-40 Medium898.10.6681
Windward/Leeward 60-40 High759.90.7895
5-Band
Windward/Leeward		Time On
Distance		Time On
Time
5-Band Low1307.60.4589
5-Band Low / Medium1083.50.5538
5-Band Medium836.30.7175
5-Band Medium / High726.40.8260
5-Band High688.40.8716
ORC Ref  03510002ED6Issued on 22/03/2023Valid until 31/12/2023
VPP ver: 2023 1.01 | © ORC | www.orc.org

Club
Certificate
2023

Boat

UNDERWOOD

ESP-5122_C

RFEV
c/ Gamazo sn
39004 Santander – España
crucero@rfev.es
Data in meters/kilograms (Metric)
HULL AND APPENDAGES (Lightship Trim)
ClassDUFOUR 31MeasurementHINPlan reviewHull constructionSolidCarbon RudderNoLight stanchionsNoTrim tabNo
LOA9.320Max. Beam3.288Draft1.819Displacement5,098Wetted area20.41IMS L7.573LSM07.420Acc. length9.320Sink (kg/mm) 14.25
VCGD-0.092VCGM-0.001RM Rated (kg·m) 78.7Limit of positive stability(°) N/AStability IndexN/A
PROPELLER
Propeller TypeSolid 3 blades
InstallationShaft non exposedTwin screwNoHydro generatorNo
PRD0.380PBWPIPA0.0087
PSD0.025PHD0.075PHL0.125
PSA10.0°ESL0.080
RIG
Forestay tensionFixedInner stayNone FittedCarbon mastNoHeadsail furlerYesMainsail furlerNoArticulated bowspritNoNon-circular riggingNoFiber riggingNoRunners/Checkstays0Spreaders1Rotating mastNo
P10.070IG11.700ISP11.900MDT10.100MDL10.110MDT2MDL2TLMWGO
E2.980J3.610BAS1.400FSD0.050SFJSPL3.700WPLTPSBD0.116MWTMCG
Flying Headsail Foretriangles IdISPTPS
FLOTATION AND STABILITY
Calculation methodRM entered directlyRM entered80.0Flotation Date01/01/2010MeasurerComment
SFFP0.760FFMFF1.230LCFcl5.394SG
SAFP8.895FAMFA0.916LCFsh5.642HBI1.093
TANKS
INVENTORY
INVENTORY
Fixed Ballast Total0
Total deductible
Total deductible
ORC Ref  03510002ED6Issued on 22/03/2023Valid until 31/12/2023
VPP ver: 2023 1.01 | © ORC | www.orc.org

Club
Certificate
2023

Boat

UNDERWOOD

ESP-5122_C

RFEV
c/ Gamazo sn
39004 Santander – España
crucero@rfev.es
MAINSAIL
IdMHBMUWMTWMHWMQWAreaMeas.DateComment0010.120.661.201.962.5418.2501/03/2023
HEADSAIL
IdHHBHUWHTWHHWHQWHLPHLUBtnFlyingFTAreaMeas.DateComment0010.040.470.891.912.074.7410.25NoNo 19.1801/03/2023
SYMMETRIC SPINNAKER
IdSLUSLESLSHWSFLAreaMeas.DateComment111.2011.2011.206.205.9557.4001/03/2023
ORC Ref  03510002ED6Issued on 22/03/2023Valid until 31/12/2023
VPP ver: 2023 1.01 | © ORC | www.orc.org