Information at a glance
DIAMETERS FOR RACING YACHTS

Sailing with all sails set in wind force 7 (approximately 30 knots or 15 m/sec wind speed). The following minimum rope diameters are recommended:
Sail area in m2
10
20
30
40
50
60
70
80
90
100

SPECTRA/DYNEEMA
SPECTRA/DYNEEMA SPORT
5
6
6/8
8/10
10
10/12
12
12/14
14
14/16
CUP SHEET
6
8
10
12
12/14
14
16
16/18
18
18/20
GEMINI
6
8
10
12
14
14
16
18
18
20
TASMANIA
6
8
10
12
14
14
16
18
18
20
RIVIERA
8
10
12
14
-
-
-
-
-
-
STANDARD
8
10
12
14
-
-
-
-
-
-
DIAMETERS FOR CRUISING YACHTS

Sailing with all sails set in wind force 5 (approximately 20 knots or 12 m/sec wind speed). The following minimum rope diameters are recommended:
Sail area in m2
10
20
30
40
50
60
70
80
90
100

SPECTRA/DYNEEMA
SPECTRA/DYNEEMA SPORT
5
6
8
10
10
12
12
14
14
16
CUP SHEET
6
8
10
12
14
14
16
16
18
18/20
GEMINI
6
8
10
12
12
14
16
18
18
20
TASMANIA
6
8
10
12
12
14
16
18
18
20
RIVIERA
6
8
10
12
14
14
16
-
-
-
STANDARD
6
8
10
12
14
16
-
-
-
-
Select the next diameter up for guys.
DIAMETERS FOR MOORING LINES, ANCHOR WARPS AND TOWING SPRINGS

The ropes in this group all need to exhibit a reasonably high stretch as well as strength. The ropes differ in that the polypropylenes (Hempex) float whilst polyamides (another name for Nylon) and polyesters sink. Floating lines are totally unsuitable for anchoring purposes! Anchor warps primarily cushion the movements of a boat by altering the "chain line" or "catenary", i. e. the sag line of the rope between anchor and hull. The heavier the rope, the better this cushioning effect will be. Polyester, as the heaviest of the commonly used materials, is the most suitable product for anchor warps, particularly as it does not harden in water (due to excessive and progressive shrinkage), or suffer unduly from tension/tension (cyclic loading) fatigue to the same degree as Nylon (which tends to be used for this application because of its higher material stretch). We do not include anchor warps containing lead in our range for environmental and safety reasons. Lead disintegrates in water and pollutes it; a parting lead cored rope and the attendant energy release can be compared to firing a shotgun in all directions at once.

For mooring lines one should weigh up the cost against the abrasion resistance of the available materials to achieve a truly cost-effective comparison.

Rope length for towing equals length of boat x 4 (x 5 in bad weather).

We recommend the following minimum diameters as a general guide, depending on length of vessel and rope type:
Length of vessel in metres
6
8
10
12
14
16
18
20
22
Polyester mooring line
10
12
14
16
18
22
24
26
28
Bavaria mooring line
8
10
12
14
16
18
20
-
-
Polyamide mooring line
8
10
12
14
16
18
20
22
26
Hempex mooring line
12
16
20
24
26
28
32
36
40

Bulloch Harbour, Dalkey, Co.Dublin, Ireland. Tel: +353 -1- 2800321( 9Lines) Fax:+353 -1- 2800327
© Western Marine 2009
Site produced in association with VooDoo