This is an unofficial forecast. The aim is to help people with their forward planning. Current wave height calculations don’t take into account the different fetches for different wind directions, nor does it take into account the duration of the wind.
Always check with CalMac for the details of the service between Brodick and Ardrossan, or Lochranza and Claonaig / Tarbert.
Thu 21st
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
05:00
Should be fine
5mph
NW
0.83ft

17%
06:00
Should be fine
9mph
NW
2.49ft

5%
07:00
Should be fine
12mph
NW
3.31ft

08:00
Should be fine
12mph
NW
3.31ft

20%
09:00
Should be fine
13mph
NW
3.54ft

10:00
Should be fine
16mph
NW
4.13ft

11:00
Should be fine
19mph
NW
4.62ft

12:00
Should be fine
20mph
NW
4.77ft

13:00
Should be fine
20mph
NW
4.77ft

14:00
Should be fine
20mph
NW
4.77ft

15:00
Should be fine
19mph
NW
4.62ft

16:00
Should be fine
18mph
NW
4.46ft

17:00
Should be fine
18mph
NW
4.46ft

18:00
Should be fine
17mph
NW
4.3ft

19:00
Should be fine
17mph
NW
4.3ft

20:00
Should be fine
19mph
NW
4.62ft

21:00
Should be fine
18mph
NW
4.46ft

22:00
Should be fine
19mph
NW
4.62ft

23:00
Should be fine
17mph
NW
4.3ft

Fri 22nd
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
17mph
NW
4.3ft

01:00
Should be fine
17mph
NW
4.3ft

02:00
Should be fine
16mph
NW
4.13ft

03:00
Should be fine
16mph
NW
4.13ft

04:00
Should be fine
14mph
NW
3.75ft

05:00
Should be fine
15mph
NW
3.94ft

06:00
Should be fine
13mph
NW
3.54ft

07:00
Should be fine
13mph
NW
3.54ft

08:00
Should be fine
12mph
NW
3.31ft

09:00
Should be fine
9mph
NW
2.49ft

10:00
Should be fine
12mph
NW
3.31ft

11:00
Should be fine
10mph
NW
2.79ft

12:00
Should be fine
12mph
NW
3.31ft

13:00
Should be fine
12mph
W
3.31ft

14:00
Should be fine
10mph
NW
2.79ft

15:00
Should be fine
9mph
W
2.49ft

16:00
Should be fine
9mph
W
2.49ft

17:00
Should be fine
8mph
NW
2.16ft

18:00
Should be fine
6mph
NW
1.34ft

19:00
Should be fine
8mph
NW
2.16ft

20:00
Should be fine
7mph
NW
1.77ft

21:00
Should be fine
8mph
NW
2.16ft

22:00
Should be fine
8mph
NW
2.16ft

23:00
Should be fine
8mph
NW
2.16ft

Sat 23rd
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
7mph
NW
1.77ft

01:00
Should be fine
6mph
NW
1.34ft

02:00
Should be fine
7mph
NW
1.77ft

03:00
Should be fine
7mph
NW
1.77ft

04:00
Should be fine
6mph
NW
1.34ft

05:00
Should be fine
8mph
NW
2.16ft

06:00
Should be fine
8mph
NW
2.16ft

07:00
Should be fine
9mph
NW
2.49ft

08:00
Should be fine
9mph
NW
2.49ft

09:00
Should be fine
9mph
NW
2.49ft

10:00
Should be fine
9mph
NW
2.49ft

11:00
Should be fine
9mph
NW
2.49ft

12:00
Should be fine
13mph
NW
3.54ft

13:00
Should be fine
14mph
W
3.75ft

14:00
Should be fine
13mph
W
3.54ft

15:00
Should be fine
11mph
W
3.06ft

16:00
Should be fine
10mph
W
2.79ft

17:00
Should be fine
13mph
W
3.54ft

18:00
Should be fine
8mph
W
2.16ft

Sun 24th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
11mph
W
3.06ft

06:00
Should be fine
8mph
W
2.16ft

12:00
Should be fine
9mph
W
2.49ft

18:00
Should be fine
10mph
W
2.79ft

Mon 25th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
20mph
NW
4.77ft

06:00
Should be fine
4mph
NW
Calm

12:00
Should be fine
5mph
NW
0.83ft

18:00
Should be fine
6mph
N
1.34ft

Tue 26th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
4mph
N
Calm

06:00
Should be fine
3mph
E
Calm

12:00
Should be fine
13mph
SE
3.54ft

18:00
Should be fine
19mph
SE
4.62ft

Wed 27th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
10mph
S
2.79ft

06:00
Should be fine
12mph
W
3.31ft

12:00
Should be fine
7mph
SW
1.77ft

18:00
Should be fine
15mph
SE
3.94ft

Thu 28th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Possibly affecting Ardrossan
16mph
S
4.13ft

06:00
Possibly affecting Ardrossan
16mph
S
4.13ft

12:00
Possibly affecting Ardrossan
22mph
S
5.04ft

18:00
Should be fine
15mph
S
3.94ft

Fri 29th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Should be fine
11mph
S
3.06ft

06:00
Possibly affecting Ardrossan
17mph
SW
4.3ft

12:00
Probably affecting Ardrossan
35mph
W
6.36ft

18:00
Possibly affecting Ardrossan
24mph
W
5.28ft

Sat 30th
Port Affected?
Avg Wind
Dir.
Waves
Wx
Temp
Fog?
00:00
Possibly affecting Ardrossan
20mph
W
4.77ft

06:00
Possibly affecting Ardrossan
19mph
W
4.62ft

Just for fun! Always check with CalMac regarding the actual status of your sailings.