Category description

Anchor Handling Tug Supply Vessels (AHTS) are an essential feature of the offshore oil and gas industry specializing in the towing, positioning and mooring of drilling rigs and other marine equipment. Equipped with powerful engine and specialized winches the duties of an AHTS vessel may include;

  • Tugging/Towing rigs, vessels are barges to location or assistance during berthing
  • Retrieving and deploying anchors

In addition to these duties AHTS are required to perform supply duties replenishing other vessels and drilling rigs in the field with operational supplies such as mud, other drilling fluids, cement, fresh water, fuel oil and miscellaneous equipment.

The wide diversity of the vessels duties also means it is often suitable to perform tasks traditionally undertaken by Platform Supply Vessels (PSV's), Multi-Purpose Supply Vessels (MPSV's), Diving Support Vessels (DSV's) or Emergency Rescue and Recovery Vessels (ERRV).

AHTS's come in a variety of sizes. These can be summarised into 4 broad categories as depicted below:

Supply & Demand Dynamics

The demand for AHTS's, and offshore service vessels (OSV's) in general, continues to be driven by the world's increased energy demands. Although over the long term global energy consumption will see a significant shift away from oil and gas, oil and gas remain a major source of consumption representing more than 50% of market share. Gas growth is expected at 1.9% p.a. and oil 0.8% p.a. through to 2035. Furthermore it is anticipated that a greater reliance on offshore resources will be seen as onshore production declines and technologies open the door to more difficult offshore resources.

The AHTS market is highly cyclical. Utilisation and rates are quick to react to oil price due to the influence oil price plays on E&P spending patterns (see Rig Count). As of mid 2018 oil prices have reached US$70 per barrel and rig count and investment has began to slowly rejuvenate. Despite this the largest challenge to owners is the huge oversupply of vessels. Because of this competition between Owners remains high and day rates low.  

Demand Outlook

AHTS demand has began to increases since the 12 year lows of US$26/barrel. Now with oil price at circa US$70/barrel confidence begins to build in the market and once uneconomical projects are under consideration again. North America, South East Asia and Northern Europe all show huge growth potential given how far the regions declined over the proceeding years however at present growth remains stagnant and will likely continue until the market regains confidence in the current oil prices. The Middle East continues with small growth in the small to mid-size AHTS tonnage due to the favourable oil economics and increasing rig activity.  

Supply Outlook

Oversupply of vessels looks to be the biggest challenge vessel owners will face for the next few years. A huge supply glut following multiple years of aggressive new-build programs remains and OSV’s out number rigs 8:1 as of early 2017 (160% increase from 2008). This holds rates and utilisation down at some of the lowest levels seen. 

Circa 24% of the global existing fleet is 20+years in age and not expected to work again. Unfortunately these numbers are offset by a continued new-build program estimated at 8-12% of existing OSV’s. Based on these economics vessel owners remain locked into challenging times for the foreseeable future. 

Regional Heat Map

With the exception of the Middle East, most regional markets have suffered the same fate during the oil downturn. See below for a snap shot of the latest trends in each region:

Key Players

The OSV market is highly fragmented. With a global fleet of circa 3,500 vessels the top 11 owners represent just less than 32% of the market. The remainder of the market is taken up by some 400-500 vessel owners with an average fleet size of 4-5 vessels. The below chart depicts the vessel split between the main AHTS & OSV suppliers.

External Scanning

A five forces analysis reveals the competitive forces acting on the market. The AHTS market is characterized by a large supply and demand imbalance, high standardisation in vessel specifications resulting in relative ease in switching to alternatives. In the present market environment power sits firmly with the buyer


Supplier Power is low

  • Lots of alternative vessels and suppliers,
  • Easy to switch vessel and supplier,
  • Suppliers are almost exclusively reliant on oil and gas industry,
  • High utilization is required to cover cost

Potential of new entry is high

  • Market has high degree of standardization
  • Chartering practises make it relatively easy for companies to manage vessels with bareboat charters
  • Vessels can move across regions easily


Competitive Rivalry is high

  • No one dominant company within region due to similar specifications and number of suppliers
  • High fixed costs

Threat of substitution is low

  • Main function of AHTS vessel is to support towing and tugging actvities therefore no real suitable alternatives exist

Buyer Power is high

  • Few buyers in region all of which tend to be large NOC's or IOC's
  • Cost of switching is low
  • Lots alternate similar specification vessels

Portfolio Positioning

Cost & Price Analysis

Due to the competitive nature of the market AHTS's owners are operating at close to breakeven with most owner's recording loses since the  downturn. The breakeven point of a small to mid size AHTS is US$5,000 to US$8,000 per day depending on region. This is broken down as follows:

Vessel prices have stabilised at very low levels compared to what has been seen in the past decade . The larger size AHTS's (Large & X-Large) see more volatility trading almost exclusively on the spot market in locations such as the North Sea and the Americas. Due to this prices month to month can range from US$40,000 per day to less than US$20,000 per day. The smaller size AHTS's (Small & Medium) see more stability with less volatility in pricing. Rates, depending on location, can range from between US$5,000 per to US$15,000 per day.

Total Cost of Ownership

Service Cost
Fuel Cost
Performance Cost
Cost Visibility
The rates and charges agreed in a contract for the performance of the service
The cost of fuel used by the vessel in performance of duties
The cost of inefficiency in performing duties

Cost Driver
  • Daily Hire Rate
  • Type of operation
  • Type of propulsion
  • Fuel Consumption
  • NPT (breakdown)
  • Learning Curve
  • Quality of work (rework, anchor deployment)
Commercial Impact


Procurement Strategy

In the current market environment buyers are in a dominant position. The huge oversupply of AHTS's, the regional mobility and low demand place power firmly in the buyers hands. Buyer’s should look to take advantage of this position securing cost reduction and higher specification vessels (fuel economy & safety). Where possible Buyer's should look to aggregate spend to further improve leverage. In summary the strategic objectives should be focused around:

When approaching the market DALEEL recommend the approach outlined below:

In preparation for any tender or negotiation Buyer's should ensure they have:

  • The latest market intelligence in the region including utilisation and indicative rates
  • The latest supplier intelligence including vessel availability, utilisation and rates
  • Information on other regions vessel availability and rates. Given AHTS's are highly mobile Buyer's should look globally and try to take advantage of lower demand in other regions.

Contracting Strategy

Typical oil field AHTS operations are managed via a Time Charter. Below is a summary of the avialble contacting methods, where responsibilities lie for each and how payment is calculated:

DescriptionPer day or duration of timeVessel hull & machinery only
Operational PreferencePreferredNot preferred
Vessel Owner ResponsibilityVessel
Vessel Only
Charterer ResponsibilityPort Charges
Cargo Loading & Discharging
Port Charges
Cargo Loading & Discharge
Calculation of ChargesDaily hire rateMonthly lump sum payment

Technical Insights

AHTS in action

Check out the video below to understand the typical operation of a AHTS:

Dynamic Positioning Explained

A DP system automatically triangulates between GPS satellites and/or other positioning systems to maintain the vessels position within a 1m to 3m radius allowing the vessels to be maneuvered very close to platforms and rigs. Check out the video below of a supply vessel operating in heavy weather in close proximity to a jack-up rig:

When engaged the DP system simultaneously and continuously controls bow thrusters and main propulsions to hold position irrespective of current, wind or wave action. This allows for greater accuracy and safety when manoeuvring removing a large portion of human error risk. DP Systems have 3 classes each representing a greater level of redundancy in the system.

Diesel Electric Propulsion Explained

Diesel Electric Propulsion differs from traditional propulsion systems in that multiple diesel engines each drive an electrical generator producing electrical power that energizes a motor connected to the propellers. This provides efficiency (fuel & emissions) benefits as when loads are low not all diesel engines will be turned on. In addition, even where one engine fails power can still be transmitted to both shaft lines.


Performance Management

Whilst awarding a contract to the right supplier is important measuring, analysing and managing performance ensures the expectation set at the outset are achieved. Below is a snapshot of where both suppliers and buyers need to focus to ensure success as well as some indicators that help identify if you are on the right path.