VESSEL REVIEW | Santa Maria – Coastal tuna pole fishing and baiting boat for operation off South Africa

Sachal Shipyard has completed construction of a new tuna pole fishing and baiting vessel for operation in South Africa’s coastal and offshore waters.

The 14.5-metre (47.6-foot) Santa Maria is a Category A-rated tuna pole vessel intended to operate all around the coast of South Africa. Her typical duties include searching for and tracking tuna schools, catching and maintaining live bait, and conducting intensive pole-and-line fishing operations over extended periods.

The vessel is designed to cope with the often demanding sea and weather conditions associated with offshore tuna fisheries while allowing the crew to work efficiently, safely, and in reasonable comfort.

“This vessel is based on the yard’s very successful range of tuna pole vessels delivered over the past few years,” Nic Stevens, Yard Manager at Sachal Shipyard, told Baird Maritime. “Together with the client, we take the lessons and feedback from each previous build and combine that with the operator’s practical experience to refine every new vessel.

“On Santa Maria specifically, we have made a number of deck layout changes to improve crew flow during fishing operations. This has been done not only to enhance operational efficiency, but also to further improve safety at sea.”

Stevens said that the yard has also been able to bring more of its larger-vessel electrical design philosophy into a vessel of this size, something that was previously difficult to do due to space constraints. The entire vessel can be run from shore power via an isolation transformer, and the electrical system is arranged around remote panels for all major consumers, simplifying operation, maintenance, and fault-finding.

Design emphasis on ease of operation and maintenance

The operator currently runs vessels under 24 metres (79 feet) in the same sector. This new vessel, being under 25 GRT and therefore significantly smaller, offers substantially reduced operational costs while still delivering the required fishing capability. Stevens expects that the lower running costs and efficient crew and catch handling will translate into improved margins and greater flexibility in how the owner deploys the vessel across the fleet.

“The main design brief was to keep the vessel simple and low-maintenance while ensuring she remains scalable for future expansion. Planned future upgrades include a net guard and associated deck gear for live-bait catching, as well as a partial shelter deck.”

To meet the “simple and low-maintenance” requirement, Sachal Shipyard focused on arranging systems and machinery spaces so that components can be easily removed and swapped out in the event of a breakdown. Stevens said this work must be able to happen quickly while the vessel is in port taking on bunkers, unloading, or preparing for a trip, ensuring that valuable fishing days are not lost.

“As with all builds that need to remain under the 25 GRT threshold, optimising layout and minimising wasted volume is critical,” said Stevens. “For this reason, a similar accommodation arrangement to the previous build was chosen.”

The master has a berth in the wheelhouse with a second berth above for the lead crewman, allowing both to remain close to the controls and fishing operations and ensuring the master can be present and well-rested throughout the trip. There is also a dedicated head accessible from inside the wheelhouse for the master.”

Below the wheelhouse is the forward accommodation space with two-tier bunks for 10 crewmembers. Aft of the wheelhouse, above the crew accommodation, is the galley and a separate head for the crew.

Immediately aft of the forward accommodation and forward of the machinery space are six insulated fish tanks with a total volume of approximately 38 cubic metres (8,400 gallons).

Proven propulsion arrangement

The vessel is powered by a Doosan MD196 main engine rated at 280 hp (210 kW) at 2,200 rpm. This drives a Dong-I DMT140 reduction gearbox, which in turn drives an 850mm four-bladed fixed-pitch propeller.

“The propeller is carried on a 70mm Duplex 2205 stainless steel shaft fitted with a Tides Marine shaft sealing arrangement,” Stevens told Baird Maritime. “We have installed many of these Doosan engines in this class of vessel with excellent feedback from operators, which is why the client opted to use this proven and reliable package.”

Sachal Shipyard focused on achieving the smoothest and quietest propulsion setup possible using a conventional shaft line and rigid engine mounts. Vibration and noise control were therefore key design drivers.

“A major reason for this focus is to minimise any interference with the advanced sonars and transducers used in modern fisheries, allowing the electronic fish-finding systems to perform at their best.”

Electronics suite configured to permit upgrades as needed

The vessel’s electronics suite is a comprehensive Furuno package, complemented by Icom and Hytera communications equipment. Navigation and fish-finding systems include Furuno TZT13 multifunction plotters with 600 W transducers, a Furuno Doppler radar for enhanced target detection, and a Furuno FCV295 echosounder with 1kW 50/200 kHz transducers.

A Furuno satellite compass and Furuno 711 autopilot are fully integrated into the navigation system. The chosen sonar is a Furuno CH500, which is planned to be upgraded to an omni sonar to further enhance the vessel’s fish-finding capability.

“Because the equipment selected is well proven in this sector, the main focus was on fish-finding efficiency, installation robustness, and overall neatness,” said Stevens. “Working closely with our electrical and electronics teams, we ensured that all installations are tidy, logically arranged, easy to fault-find, and scalable. This approach makes future upgrades and additions simpler and less disruptive.”

There is a 2.2kW warping head winch on the main deck amidships, and this will be used for recovering the parachute/sea anchor while the vessel is drifting in search of fish or waiting for weather windows.

“This is the first time we have fitted an electric winch on this type of vessel for parachute handling. On previous vessels, this operation was always carried out manually, so this represents a significant improvement in crew safety and efficiency.”

Flexible RSW tank setup

The refrigeration system is an RSW setup that circulates refrigerant through stainless steel cooling coils installed in each fish tank.

The system is designed to maintain tank temperatures at around minus five degrees Celsius for fresh fish in chilled seawater, minus 16 degrees Celsius for frozen fish in brine, and approximately minus 10 degrees Celsius in one of the tanks configured as a frozen bait hold. This provides a high degree of flexibility in how both catch and bait are handled and stored.

“To keep the refrigeration system fully optimised, we run seawater circulation systems in each fish tank/hold,” Stevens told Baird Maritime. “These are equipped with pumps designed for 100 per cent duty cycle and installed with redundancy.”

The system is configured so that any tank can be filled, emptied, or its contents transferred to or from another tank, or circulated individually. All six tanks are linked to this system, giving the operator maximum flexibility.

“As with all custom and semi-custom builds, there are always numerous smaller innovations on every project. Because this vessel is based on a previous successful and similar design, the focus was mainly on refining and improving existing systems rather than introducing entirely new concepts.

"These refinements – in layout, systems integration, access, and maintainability – collectively result in a more efficient and user-friendly vessel for the operator and crew."

Because Santa Maria is a compact fishing vessel, space-saving was a paramount consideration during the design phase, and Sachal Shipyard needed to achieve this while still maintaining operational effectiveness.

“It is easy to design complex systems,” said Stevens. “The challenge is to design complex systems that are simple to operate and maintain. This is what the yard’s design team consistently strives for on our builds.

“We also had to allow for future hardware installations without having final specifications for that equipment. This meant allocating sufficient space and carefully planning system routing and penetrations for electrical services and piping so that future installations will be straightforward and won’t require major structural or layout changes.”

The tight build timeline also posed a key challenge for Sachal Shipyard. The vessel needed to be ready to fish for the upcoming season, which placed pressure on every stage of the project. Meeting the schedule was also important in terms of optimising the cost of capital for clients who have invested in the build, ensuring they can start generating returns as soon as possible.

"This was the first vessel on which we incorporated our own aluminium weathertight hold access hatches and coamings, which proved to be very successful in service and will be carried forward to future projects," Stevens told Baird Maritime. "Any learnings on the production side are always welcomed, as they help us further improve build efficiency, quality, and consistency on subsequent vessels."