ADCP's Application to Ocean Current Measurement in Los Cristianos Port

1. Where is Los Cristianos Port?

Los Cristianos is one of the well-known coastal towns in the south of the Tenerife island in the Canary Islands, Spain. The port of Los Cristianos is one important maritime facility serving both local and tourist-related activities.

Port Scale and Throughput

The port has a moderate scale. It is well - known for handling a variety of vessels such as small - to - medium - sized fishing boats, ferry boats, and a significant number of tourist - oriented vessels like catamarans and pleasure boats. The throughput is quite high during the peak tourist seasons as it caters to a large number of tourists who take boat trips for whale - watching, island - hopping, and other excursions. It also handles the landing and distribution of the local fishing catch.

Routes and Business

It has a wide network of routes that link it to other ports within the Canary Islands and some mainland Spanish ports. Tourism-related transportation, especially in ferry services across to neighboring islands such as La Gomera and El Hierro, forms the main business activity. It also caters for local fishing with facilities for the docking of fishing vessels and a marketplace for the sale of fish.

Management and Operation of Port

The port is operated, keeping in view safety and efficiency for a range of vessels. The authority handles berthing and unberthing of the ships and passenger and cargo flow, keeping safety parameters. They make sure that the services related to tourism like ticket-selling, boarding formalities, and upkeep of waiting areas are being carried without glitches.

Port Facilities

Various facilities are available in this port. It has several berths of varying sizes to handle both larger and smaller vessels. It has the loading and unloading machinery suitable for fishing gear, supplies for boats, and passenger luggage. There are storage areas for fishing equipment and some perishable goods. Facilities also include refueling installations for boats and basic maintenance services.

Channel and Direct Shipping

The depth of the channel in the port is maintained in such a way as to allow vessels it serves to pass through without any risks. It has direct shipping links, which are crucial for the delivery of tourists and goods. It cuts down the travel time and cost, which makes the destination more attractive both for tourists and local businesses.

2. Why should we measure the ocean currents in the Los Cristianos Port?

Measurement of currents in Los Cristianos Port is an indispensable activity due to various reasons: first, in regard to vessel and boat safety, only accurate current data can be reliable. The area's ocean currents may affect vessels' speed and direction when coming in or leaving from the port. These are important aspects on which the captains and the boat operators take action for collision avoidance in order to maintain safety for both passengers and the vessels themselves.

In relation to tourism-related activities, ocean currents are important in the following ways: For boat trips such as whale-watching and island-hopping, knowledge of currents will help in planning routes that are more efficient and comfortable. This also concerns the stability of the boats, which is important for tourist safety and enjoyment.

It will help the fishing industry by knowing in advance where fish gather and what time of day to venture out and come back. Further, it becomes fundamental to the preservation of the structure in the ports, given that good knowledge of currents is important to foresee sediment transport for the adequate dredging plans to maintain depth throughout channels and berths in the ports.

The ADCP current meter is a newer, more efficient, and more convenient technique for current measurement. It could provide real-time and multi-depth current data in a very practical way for the operation and management of the port.

3. How does an ADCP using the principle of the Doppler work?

Working principles of ADCPs are based on the Doppler effect. They send acoustic signals into the water. These signals interact with particles or any other substance that might be moving with the water current. When these acoustic signals are reflected back, the frequency of the reflected signals changes due to the Doppler effect. By analyzing this frequency shift, the velocity of the water current can be calculated.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Operating within the area of a port, the ADCPs are mounted on ships, sending acoustic pulses from the moving vessel down and laterally. Each of these pulses can measure current velocities at depths relative to a line traced in space by a vessel. That would show real-time current vectors transmitted into the ship's control system. The crew thus controls the vessel accordingly in their course or speed.

Fixed ADCP

Fixed ADCPs are deployed at fixed locations in the port, such as on the seabed or on the side of port structures. They continuously monitor the ocean currents in a particular area. The data collected by fixed ADCPs provides a long - term understanding of the current patterns in the port, which is useful for port planning and infrastructure maintenance.

4. What is needed for good-quality measurement of Los Cristianos port currents?

The equipment to be used for current measurement in the Los Cristianos port should be made of reliable materials that could bear up to the harsh marine environment: corrosion by seawater and pressure variations. Smaller size, lighter weight, and low power consumption are preferable. A compact size makes installation easier and more versatile for various locations at the port. Small power consumption assures longer-term operability without frequent battery exchange or problems connected with power supplies. Cost efficiency is also considerable to allow deployment of measurement devices on a larger scale.

The casing of ADCP profiler should be manufactured using titanium alloy. Because of its really good resistance to corrosion, in seawater and in long-time work, it is impossible to manage without titanium alloy. Besides, having high strength with a high strength-to-weight ratio, it is able to bear high pressure and add no excess weight. Moreover, it is a biocompatible alloy that doesn't considerably influence the marine environment.

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

Usage Purpose

• Shipborne ADCP: A shipborne ADCP would be ideal for measuring currents during the movement of ships. This gives real-time data about the current conditions that this ship is sailing through within the port and thus helps with its navigation and operational safety.
• Sitting-bottom ADCP: Good for long-term fixed-point monitoring of the same area inside the port. It will give a continued view about what happens in this area, and it is advantageous for a basic understanding of long-term current patterns and in maintenance of the port infrastructure.
• Buoy-mounted ADCP: Convenient for areas where it is not practical to install fixed equipment on the seabed or on ships. The buoy-mounted ADCP can float on the water surface and measure the currents around it, thus allowing flexibility in measurement locations.

According to Different Frequencies

• The water depth up to 70m will be adequately covered with a 600kHz ADCP since it can provide fairly accurate current measurements in relatively shallow water.
• A 300kHz ADCP would be more appropriate for a depth of about 110m, since at that depth the ADCP would effectively measure the current.
• A 75kHz ADCP will be quite adequate for waters up to 1000m for reliable current measurement.

There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, the Chinese brand China Sonar PandaADCP is also a great option. It is made of all-titanium alloy material and offers an excellent cost-performance ratio. You can visit its website (https://china-sonar.com/) for more information.

Here is a table with some well known Acoustic Doppler Current Profiler(ADCP) instrument brands and models.