Search and Rescue Transponders (SARTs) are a compulsory piece of GMDSS equipment that ships need to carry. In accordance with SOLAS, Chapter 4, the number of SARTs you need depends on the size and type of vessel.

One (1) SART is required on vessels between 300 GRT and 500 GRT. Two (2) SARTs are required on vessels over 500 GRT. In addition to that, ro-ro passenger ships need enough SARTs to have one (1) SART for every four (4) liferafts.

How many SARTs do Different Ships Require?

SOLAS regulations break down SART carriage requirements depending on the type and size of vessel.

How many SARTs do Cargo Ships Require?

Small cargo ships, less than 300 GRT, do not need to carry a SART. To give you an idea of the size of a 300 GRT ship, this 40m Coastal Patrol Vessel by Fassmer is 245 GRT.

Cargo ships between 300 GRT and 500 GRT only need to carry 1 SART. Again, to give you an indication of this size of ship, this 50m supply vessel has a gross tonnage of 525 GRT.

Once your cargo ship exceeds 500 GRT, you need to carry at least two SARTs. This includes everything from small coasters trading locally, right the way up the world’s largest container ships.

How many SARTs do Passenger Ships Require?

Most passenger ships need to carry at least 2 SARTs. There is not the same distinction as there is with cargo ships. No matter how small, every passenger ship needs to carry at least 2. Given that the definition of a passenger ship is any vessel that can carry 12 passengers, you can see that even small ones will need to carry 2 SARTs.

When that passenger ship is also a ro-ro ship though, the amount they need to carry increases depending on the number of liferafts onboard. These ships need to carry at least 1 SART for every 4 liferafts in addition to the 2 that they need for the ship.

So, for example, if a passenger ro-ro has 10 liferafts on each side of the vessel, at least 5 liferafts need to have a SART. That is in addition to the 2 that the ship itself needs to carry. Therefore, she would need at least 7 SARTs in total.

How many SARTs do Pleasure Boats Require?

Pleasure boats that are not subject to international conventions do not normally need to carry a SART. There may be specific local regulations that do require carriage, but I am not currently aware of any.

There is always the option of carrying one voluntarily though. You might consider it if you want to increase your provision of safety equipment.

It is often a requirement to carry a radar reflector, but that should not be confused with a SART.

What is the Difference Between a SART and a Radar Reflector?

You may have heard of radar reflectors, and may even have considered putting them in the same category as a SART. There are, however, some crucial differences between the two.

SARTs are active devices, designed to transmit a signal when it detects a radar in operation nearby. Radar reflectors are passive, and designed to increase your visibility by giving a surface that reflects a radar pulse back to the vessel that transmitted it.

SARTs and radar reflectors cannot be used interchangeably. They are designed to fulfil two different roles.

What Type of SARTs do Ships need to Carry?

There are two broad categories of Radar Transponder that you can buy. Ones that have AIS built in, and ones that don’t.

Strictly speaking, a SART does not need to have AIS fitted at all. A Search and Rescue Transponder is simply a device that indicates its position on the screen of a 9GHz radar. When it detects a 9GHz radar in operation, it transmits a series of pulses that paint a distinctive pattern on the radar screen.

AIS SARTs enhance that by transmitting an AIS target in addition to an active radar return. Vessels searching for you would see an AIS return as well as the distinctive radar return on their screen. It just increases your visibility if you find yourself in a distress situation.

Despite the increase in visibility, the requirement is only for a “radar transponder”. As such, ships only need to carry regular 9GHz SARTs, not an AIS SART.

It is, however, permissible to carry an AIS SART instead of a regular SART. If you chose to do so.

Where do SARTs need to be Located?

SARTs need to be located in a position where they are easily accessible, and can be easily placed into survival craft.

On ships that need to carry multiple SARTs, they need to be stored on either side of the vessel.

Where do SARTs need to be Located on a Cargo Ship?

Cargo ships over 500GRT need to carry one SART on each side of the vessel. The only additional guidance is that they need to be stored in a location that means they can be rapidly placed into survival craft.

The most common location I have seen is with one SART located on each side of the navigational bridge. From the bridge, it is usually only a short distance to the survival craft.

An alternative is to store SARTs next to each survival craft. This makes it easy to transfer the SART to the craft itself, but makes it harder to use from the ship. Ideally, you would have an additional SART on the navigational bridge in case you need to use it on the ship itself.

Where do SARTs need to be Located on a Passenger Ship?

Passenger ships need to carry one SART on each side of the vessel.

In my experience, most passenger ships carry a SART of either side of the navigational bridge, and usually additional SARTs near to the lifeboats.

Ro-ro passenger ships that need additional SARTs for liferaft will have them mounted inside the liferafts themselves. As we said previously, there will be 1 SART for every 4 liferafts. You should expect to find rafts with SARTs clearly marked and spread across the storage locations.

Where do SARTs need to be Located on a Ship with Free-Fall Lifeboats?

When a ship has a freefall lifeboat, one of your SARTs needs to be stored within the free-fall lifeboat. The other one should be stored in the immediate vicinity of the navigational bridge. Storing the other one near the bridge means it can be transferred to a survival craft, or used on the ship itself.

The regulations do state that the SART only needs to be stored in the freefall lifeboat if the ship needs to carry two SARTs. Saying that, it is quite unlikely that a cargo ship <500GRT would have a freefall lifeboat.

Further Reading

Regulations for the carriage of SARTs are laid out within SOLAS. The International Convention for the Safety of Life at Sea. You can read up on the regulations within SOLAS itself, or within the national laws of each signatory country.