ADCP Applied to Ocean Current Measurement in El Nido Port

1. Location of El Nido Port

El Nido Port is located within the municipality of El Nido in the province of Palawan, Philippines. For being proximal to many of the most beautiful and varied marine ecosystems on the face of the planet, it qualifies as a notable port.

Port Scale and Throughput

It is a medium-scale port, well adapted to the demands of tourism and local trade. It deals with a considerable number of tourist boats and small to medium-sized cargo vessels. The number of vessels can spike during the peak tourist season. The port is an important gateway to the tourists visiting the beautiful lagoons, beaches, and coral reefs of El Nido. Local produce, handicrafts, and construction materials are also moved through this port.

Routes and Business

El Nido Port is connected to other Philippine ports through various domestic routes. Tourism is the mainstay of its business. Tourism activities in famous destinations like the Bacuit Archipelago result in several tourist boats going up and down. A lot of fishery activities also are supported by this port wherein fishermen base their fishing vessels within this port and are allowed to sell their daily catch at better prices to consumers directly. The port initiates local product trades for other economic activities in the place.

Port Management and Operation

It operates under the management of the local port authorities who see to its operations with smoothness and efficiency. They oversee tasks, which run from control of vessel traffic so as not to overcrowd both tourist and fishing boats to proper berthing arrangements so space is put to good use. In maintaining the environment, the Port Authorities also clear up any litter and other forms of messiness so as to give tourists the best impression possible. Security is paramount, hence they work with the local enforcement and other maritime security organs to secure the port and its patrons.

Port Facilities

The port has various types of berths, serving different categories of vessels. There are docking areas put up in a way as to accommodate the needs brought about by tourist boats, particularly ease of access to and from the boats by passengers. It also has storage houses for fishing gears and other supplies, areas for storage and display of local handicrafts, cafes, restaurants, and information centers for the tourists. It has fueling stations and equipment for cargo loading and unloading.

Channel and Direct Navigation

It has a well-maintained channel in El Nido Port that enables safe navigation. For many such facilities, regular dredging operations must maintain channel depth so that any particular vessel draft can comfortably stay in. The channel is laid with buoys and beacons in the pattern as prescribed for lateral channel marking, besides lights mounted at appropriate locations. Without this, it would hardly have been possible to view paths through direct navigation by seamen past shallow areas and hence safer zones to enter or clear a port.

2. Why does one need to measure ocean currents in the El Nido port?

Improved Tourism and Recreation

Ocean current measurement in El Nino Port has importance from the point of view of tourism. Current data shall be used by tourist boat operators in route planning, keeping in mind efficiency and comfort. By knowing the direction and speed of the currents, they can provide a smoother ride for passengers, reducing seasickness and enhancing the overall experience. Knowledge of currents aids in site and time selection for water-based activities such as snorkeling and diving. Currents can affect the visibility and the presence of marine life, so more accurate measurements can lead to more memorable and enjoyable experiences by tourists.

Optimal Fishing Operations

The measurements of ocean currents are one of the most valuable things connected with the fishing industry. Currents transport nutrients, which are essential for marine life, and greatly distribute fish and other species across wide areas. By properly measuring these currents, fishermen will know places where the concentration of fishes is higher and, correspondingly, the movement pattern of the fish. This will immensely increase their catch and their productivity, thereby sustaining their local economy in the process.

Efficient Port Operations

Correct current measurement forms the basis for efficient berthing and mooring. Ocean currents can affect vessel movement, and if properly pre-informed about current conditions, port operators will be better positioned to berth vessels. This reduces the occurrence of any collision and helps to avoid damage to vessels and port facilities. This is of especial significance in the busy port of El Nido, with its combined mix of tourist and fishing vessels.

Infrastructure and Environmental Protection

From an infrastructure perspective, today's measurements constitute very useful information for the maintenance and future planning of the port structures. Currents can exert a considerable force on piers, breakwaters, and other facilities within the ports by affecting their stability and longevity. Besides purely physical implications, the understanding of currents is relevant from an environmental management viewpoint. Currents are helpful in modeling dispersion of pollutants and any other substance in water, which can enable appropriate waste management for the protection of the rich marine environment at El Nido.

Acoustic Doppler Current Profiler (ADCP) is far more sophisticated and handier in terms of measurement of ocean currents compared to conventional techniques. It provides real-time and detailed current profile information, hence enabling far more accurate and efficient monitoring of the ocean currents within the port area.

3. How do ADCPs using the Doppler Principle Work?

The principle of operation for ADCPs is based on the Doppler principle. ADCPs transmit acoustic signals into the water. The acoustic waves scatter off the moving particles in the water, such as suspended sediments or small organisms. Due to the striking of the acoustic waves against the moving particles, the frequency of the reflected waves shifts according to the Doppler effect.

This frequency shift of the reflected signals is measured by the ADCP meter. By using some specific algorithms and calibration, it can work out the velocity of the moving particles. Since these particles are moved mainly because of the ocean current, it can calculate the velocity of the current.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are installed on vessels operating in the port area. The ADCP current meter continuously sends out acoustic pulses while the ship moves through the water. Normally, the pulses go to the bottom and to the sides of the vessel. Current velocities at various depths across the track of the vessel are measured by the ADCP profiler. Data obtained in a pass of the ship could be used to develop an extensive map of the current field in a port area. This, in turn, allows for in-depth information about the prevailing patterns throughout the journey of the vessel.

Fixed ADCP

Fixed ADCPs are used in fixed locations in the port, for example, on the seabed or from fixed structures like piers or breakwaters. Fixed ADCPs carry out continuous recordings of ocean currents in one location over time. Data derived from fixed ADCPs are fundamental in identifying long-term and steady current conditions at key points of the port. It shall serve as a reference to operations, research, and basic infrastructure planning of the port.

4. What's needed for high-quality measurement of El Nido port currents?

Equipment Requirements

This in turn presupposes that equipment for ocean currents measurement intended to be used within El Nido Port has to be made from resistant materials to harsh marine conditions, such as salinity/chemical composition of seawater, high pressure at greater water depth, and even impact caused by floating debris.

Also of consideration are the size and the weight of equipment. It has to be made in compact size and relatively lightweight so it can be fitted easily onto vessels or wherever there might not be a much-open space on fixed platforms. The ease of the application would be feasible.

Power consumption is another important factor that is considered. A low power-consuming device will be good for operation over an extended period without requiring speedy battery changeovers or high energy input. This is significantly related to fixed ADCPs that may be deployed in places with not-so-easy access to power supplies.

Titanium Alloy Casing Advantage

ADCPs whose casing are of titanium alloy prove to be one of the best options. Its resistance to corrosion is good, therefore guaranteeing long use in seawater without corroding. This way, the integrity and performance of the ADCP flow meter are maintained. It also possesses a high strength-to-weight ratio, hence allowing for lighter yet durable structural design. That is beneficial not only for its installation but also for operations. Also, titanium alloy can resist high pressure in a greater depth; thus, it is suitable to be used in various water depth conditions in the port area.

5. How to Choose the right equipment for current measurement?

Based on Usage

Shipborne ADCP: When the intent would be to gain a general overview of current patterns inside the port while there is vessel traffic, then this device, which is installed aboard ships, is very suited to it. As the ship covers most areas around the facility by sailing in them, large coverage of current view or rather wide-ranging currents will come about.

Bottom-mounted (Sitting on the seabed) ADCP: In the case of long-term and continuous monitoring at fixed locations, such as near important port structures or where the current characteristics are of particular interest for research or operational reference, bottom-mounted ADCPs are more appropriate. They are able to provide stable and consistent data over an extended period.

Buoy-mounted ADCP: When it becomes difficult to measure the currents in areas that are inaccessible by fixed installations or even ship operations, buoy-mounted ADCPs can be employed. Such ADCPs, while moving with the currents to some extent, may collect the data on the variation in those currents in those particular areas.

Based on Frequency

Water depth within 70 m, a 600 kHz ADCP would generally be a good choice for most applications because it could provide detailed, accurate current measurements in the fairly shallow parts of the port.

To a water depth of as much as 110 m, the ADCP of choice is a 300 kHz one. This would serve very well through the water column to provide reliable current data at that depth.

ADCP of frequency 75 kHz can be used for deeper areas with water depths reaching 1000 meters; it can cover such large depth ranges and still measure the ocean currents with acceptable accuracy.

There are several well-known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, it's worth mentioning a cost-effective Chinese ADCP brand-China Sonar PandaADCP. It is made of all-titanium alloy material and offers an impressive price-performance ratio. You can visit its website at (https://china-sonar.com/) for more information.

Here is a table with some well known ADCP instrument brands and models.