The Boscombe surf reef waits for structural repairs

July 6, 2010 | Surfing
Boscombe surf reef: a dream waiting to come true

The Boscombe artificial surf reef will try to understand why the £3m project is not performing as it should.

On Tuesday, July 13, Bournemouth councillors will ask what should be made to have 100m surf rides of 15 seconds.

A few months ago, the performance of the Boscombe surf reef was studied in detail by the Plymouth University.

The results were pretty clear: only 33% of the overall objectives were achieved by the new Boscombe surf reef. Let's hope everything gets fine tuned soon.

Here are the standards for evaluating the Boscombe surf reef:

1 Surfability Whether the wave is surfable or not? The wave should be surfable (rides lasting >3s) by stand-up surfers of appropriate experience, (Hutt scale 5 and above). Yes – the artificial surf reef at Boscombe has successfully created a new surfing resource.
2 Wave Quality Ride length

≥65m Right

≥20m Left

This ride length must be achieved with some consistency by surfers (e.g. >10% of the rides)

Left – Yes

Right – No

3 Wave Quality Wave Form The expectation is that the reef will produce waves which have, “steep faced (steeper than the neighbouring beach) but rarely barrelling and suitable for competent surfers to execute standard manoeuvres”. A plunging wave is anticipated at take-off. Yes
4 Wave Quality Peel angle

70o±10o Left

60o±5o Right

Left – Yes

Right – Partially

5 Wave Quality Wave height amplification ≥+20% on ambient levels Yes – providing the wave conditions are suitable to break on the reef and the tidal state is optimal.
6 Consistency Number of surfable days compared to the beach The expectation is that the reef will at least match the beach in terms of the number of surfable days. No – evidence indicates that surfing conditions are less consistent than the beach.
7 Surfer numbers Is the reef being surfed? A lack of surfing by surfers at the reef when conditions are appropriate for surfing at the pier will indicate sub-standard reef performance No – the reef is being surfed but less consistently than the beach.
8 Surf Quality Grade of wave

Quality of surf on a given day is improved using ASR Scale:


4-6: Waves <1m

6-7: Waves >1m

Compared to the Beach:


Generally, the reef is suitable for level 5 surfers and above with level 6 & 7 surfers enjoying a higher number of successful rides:

5-6: Waves <1m

6-7: Waves >1m

9 Wave Quality Wave Quality A low number (between 1 and 5 days/year) of exceptional quality waves are produced on the reef. Partially successful, although ride length needs to be extended to fully satisfy this condition.
10 Conformation to design specifications Physical shape of the finished reef

Crest height: 0m ACD

Length: 120m

Orthogonal Gradient: <1:15 to 1:20

Crest height – No

Length – Yes

Orthogonal Gradient – Yes

11 Wave Quality Vortex ratio A plunging wave with a vortex is only expected during larger wave conditions (Hb>1 m) and primarily on take-off on the right. Given the design orthogonal reef gradient and the grading of the reef it is expected that the vortex length to width ratio should be >2. Not yet quantified but appears to be consistent with expectation.