Photos, figures, and story by S.A. Martin
Prince of Songkla University

This article explores 4 types of ocean currents found at 5 beaches in southern Phuket. The purpose of

the article is to clarify and map problematic areas where tourists and residents alike get into trouble in

the water. When ocean currents become especially strong, they are normally identified as Rip Currents.

There are mainly 4 types of ocean currents found at Phuket beaches, namely fixed currents, headland

currents, flash currents, and longshore currents. When these currents combine, the affects are additive

and very strong rip currents may occur.

This article does not discuss swell types and other phenomena related to ocean currents or safety in

Phuket (see the Ajarn Surf article in TSM issue # 3 for insights on the implications of swell types, such as

windswell and groundswell, on coastal currents). Please see the PHUKET OCEAN SAFETY GUIDE in

the Resources menu? for surf beach safety tips and what to do if you get caught in a rip current.

WHAT IS A RIP CURRENT?

A rip current is a strong nearshore ocean current.

A rip current is a nearshore ocean current which can carry a person out to sea.

A rip current is any strong nearshore ocean current caused by THE SURF!


4 TYPES OF RIP CURRENTS AT PHUKET BEACHES

FIXED CURRENTS

Most beaches in Phuket have specific areas where ocean currents are strongest. Fixed currents

generally occur around the same area and direction from day to day.

For example: all beaches!

HEADLAND CURRENTS

Many headland areas at Phuket beaches have rip currents. These currents can permanently occur at

one particular end of a beach, where the sand meets the rocks and jungle. They are especially strong

when there is SURF.

For example: the southern end of Kata Beach; the northern end of Kata Noi Beach; the southern end of

Nai Harn Beach.

FLASH CURRENTS

Strong nearshore currents can suddenly and unexpectedly appear in Phuket, especially after a series

of waves. Flash rips in Phuket can be caused by a mixture of wave types and conditions which combine

with additive affects.

For example: All beaches! Especially during high tides at Karon Beach, the southern end of Kata Beach,

and the southern end of Nai Harn Beach.

LONGSHORE CURRENTS

Long-straight beaches have year-round currents which move parallel to the shore. These currents may

increase in speed and power as wave activity increases. Normally, longshore currents are found inside

of the surf zone.

For example: Karon Beach.

In the following diagrams, arrows mark the various ocean currents. Larger-sized arrows indicate

the predominate currents. Red arrows mark areas that are infamous for flash rips.


Karon Beach

This long-sweeping beach is especially open to wave and wind

activity from the south, the west, and the north. Unique to

Karon Beach, and at the onset of the monsoon season, the

sand bars shift into ?sand channels? which form perpendicular

to the beach. Sand channels are areas of shallow water which

act as obstacles, directing the water carried in by the surf to

return to sea between them, resulting in rip currents. Karon

beach rip currents can be of considerable intensity depending

on the wave height, frequency and tides. Fixed rip currents

at Karon can be found just north of the lifeguard tower at the

Karon circle and park area. Furthermore, as Karon is some

3 kilometers long, it is akin to strong longshore currents.

Longshore currents may build up strength as the water

moves parallel to the beach in the direction of the waves (i.e.

southwest swell direction may produce northerly longshore

currents).

Karon Beach lifeguard Dhartree Promnoon identifies that

during the southwest monsoon, there are as many as 18

distinct rip currents (fixed rips) and a pervasive inshore ocean

current which flows from south to north along the beach

(2010 personal communication). Thompson (2010 personal

communication) notes that inshore currents at Karon Beach may

suddenly shift or change direction, posing precarious dangers

for tourists who are unfamiliar with surf beaches.

Raab (2010 personal communication) who grew up surfing

the big waves of Hawaii?s ?North Shore? attests to the strong

currents associate with the sand channels at Karon Beach,

?I got caught in a rip once while swimming at Karon. I used

to go back frequently to Hawaii, so the head-height waves at

Karon looked small to me, yet I still got in a little trouble and

had to swallow my pride and swim across the rip for a long time

and try to body surf in with the waves. Imagine if you weren?t

used to the ocean and the waves.?

Sand channels and associated currents may be difficult to

recognize for individuals without significant ocean experience

and local knowledge of the area. In Hawaii, county lifeguards

place red flags to mark these channels and keep the swimmers

out of the area (Davis, 2008 personal communication).

Lifeguards at Karon are doing this now as well (Dhartree

Promnoon, 2010 personal communication).

Surin Beach

A characteristic of the ocean currents at Surin Beach is that

they may change dramatically depending on tides and swell

directions, making it difficult to identify hazards associated

with surf activity. Wave activity tends to focus on the central

and northern areas of the beach. According to Remmers (2009

personal communication), during periods of average to high

surf, there are normally four distinct fixed currents directly off

of Surin Beach. During especially high surf, the four currents

illustrated combine into two large rip currents (ibid.).

Anthropogenic changes at Surin Beach

Thai elders who live in the Surin Beach area recount that the

coral reefs which once spanned from the shoreline to the

surrounding waters have all but vanished due to the tin mining

industry (Aiyarak, 2008 personal communication). It is plausible

that coastal currents were considerably altered due to the loss

of these reefs. Given the deeper seafloor bathymetry of Surin

(in comparison with nearby beaches) it may be more susceptible

to the aforementioned effects of groundswell which can

produce flash rips.


Kata Yai Beach

Kata Yai Beach is indisputably Thailand?s number one surf

beach. Although the berm of the beach is less steep than Surin

and Karon, it is reasonably similar in nearshore bathymetry.

During the monsoon season, sand banks develop offshore

(mainly at the southern half the beach) and the bay becomes

shallower. Wave activity tends to focus around the southerly

end of the beach and correspondingly, the ocean currents

around the south end of the beach are normally the strongest.

Currents at Kata Yai Beach are more predictable than those

occurring at Surin and Karon. During wave activity, a headland

current develops along the rocky shoreline at the southern end

of the beach which pulls directly out to sea. This current is

often utilized by surfers as a method of getting out to the open

ocean quickly, but for a novice or average beachgoer, this

current may move faster than that of a strong swimmer.

Approximately 200 meters to the north of the southern

headland, flash rip currents are common, particularly during

high tides. This is especially problematic given the volume

of swimmers in correlation with the rapid onset of these fastmoving

flash currents.

Kata Noi Beach

Kata Noi Beach is unique in Phuket in that it receives even

the smallest wave activity, including southwest groundswells

during the shoulder and high seasons. This is to say that at

a time when other beaches in Phuket may have little or no

wave activity or rip currents, Kata Noi Beach may indeed have

surf and associated currents. Rip tides at Kata Noi Beach are

defined by a perpetual strong current at the north end of the

beach which follows the rocky shoreline directly out to sea

(a headland current). This area should be avoided by swimmers.

During periods of the slightest wave activity, the current can

without doubt move faster than even an experienced swimmer.

Local Thai surfer Tongooni (2008 personal communication),

who has surfed the area for the previous decade indicates that

tourists repeatedly have difficulties in this area.

Nai Harn Beach

Nai Harn Beach is somewhat similar to Surin and Karon

beaches in as much as the nearshore sand bars give way

to deep water. However, the large bay fronting the beach is

much deeper than most other Phuket surf beaches. Therefore,

a characteristic of wave activity at Nai Harn Beach is ?punchy?

waves (called plunging breakers) associated with strong

nearshore currents. The predominate rip currents occur at

the southeastern end of the beach near the rocky headlands

(headland currents) where the best surfing waves are propagated.

Rip currents occur along the rocky headland may take

swimmers directly off shore and into the surfing area.

A second rip current results from the backwash resulting from

sand banks associated with the estuary at the southeastern

end of the beach and pulls parallel to the beach and then

bends toward the open sea. This area is notorious for tourist

drowning and is the most common area where surfers

rescue-assist swimmers in distress. Furthermore, a large rip

current (fixed rip current) normally forms near the center of the

beach and extends well offshore into particularly deep water.

References

Martin, S. A. (2010). The Surfer-Lifesavers of Phuket.

Thailand Surfrider. (3) 40-42. Thalang, Phuket: Purple Diamond Ltd.

Aiyarak, C. (2008, January 29 & September 30; 2009, March 18; 2010, June, 26).

Phuket Boardriders Club. (Personal communication).

Chayangkanon, S. (2010, January 8). Royal Phuket Marina, Phuket, Thailand.

(Personal communication).

Davis, L. (2008, September). Sugar Palms Hotel, Kata Beach. (Personal communication).

Jubrik, T. (2009, June 12). Kalim Beach, Phuket, Thailand. (Personal communication).

Pawinnaporn, J. (2009, March 12). Kata Noi Beach, Thailand. (Personal communication).

Promnoon, D. (2010, July 24). Karon Beach, Thailand. (Personal communication).

Raab, M. (2010, February 20). Telephone communication, Phuket, Thailand.

(Personal communication).

Remmers, L. (2008, September 15; 2009, March 19). Bang Tao Beach; Kamala Beach,

Phuket, Thailand. (Personal communication).

Tachiban, H. (2010, February 25). Kata Beach, Thailand. (Personal communication).

Thompson, L. (2009, August 16; 2010, August 21). Kathu, Phuket, Thailand.

(Personal communication).

Tags

 
 

0 Comments

You can be the first one to leave a comment.

Leave a Comment