A rescue craft is a boat

Boat

A boat is a watercraft of any size designed to float or plane, to provide passage across water. Usually this water will be inland or in protected coastal areas. However, boats such as the whaleboat were designed to be operated from a ship in an offshore environment. In naval terms, a boat is a...

, ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

 or aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 used in rescuing

Rescue

Rescue refers to responsive operations that usually involve the saving of life, or prevention of injury during an incident or dangerous situation....

.

The most common are Lifeboat (rescue)

Lifeboat (rescue)

A rescue lifeboat is a boat rescue craft which is used to attend a vessel in distress, or its survivors, to rescue crewmen and passengers. It can be hand pulled, sail powered or powered by an engine...

 for Inshore and closer to shore rescues. For operations further out from shore helicopters & ships are mainly used.

Most Government agencies rely on larger ships for rescues further from shore such as Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 ships in the United Kingdom and Coast Guard Cutters

United States Coast Guard Cutter

Cutter is the term used by the United States Coast Guard for its commissioned vessels. A Cutter is or greater in length, has a permanently assigned crew, and has accommodations for the crew to live aboard...

 used in the USA (Although the UK Coastguard does use larger vessels to tow ships in distress). Similarly the UK uses both the Royal Air Force SAR

RAF Search and Rescue Force

The RAF Search and Rescue Force is the Royal Air Force organisation which provides around-the-clock aeronautical search and rescue cover in the United Kingdom, Cyprus and the Falkland Islands.-History:...

 and UK Coastguard

Her Majesty's Coastguard

Her Majesty's Coastguard is the service of the government of the United Kingdom concerned with co-ordinating air-sea rescue.HM Coastguard is a section of the Maritime and Coastguard Agency responsible for the initiation and co-ordination of all civilian maritime Search and Rescue within the UK...

 for helicopter rescues and the USA uses the United States Coast Guard

United States Coast Guard

The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...

 for theirs.

Sea

There were attempts as early as the 14th century to aid shipwreck victims with the Chinese training in resucitation for the drowning, as well as Portugal and Sweden in the 1690s ordering that ships should be sent to sea to rescue shipwreck survivors, but the first mention of lifeboats was in China where boats were used to rescue people from the rivers in 1737.

Air

The development of the sea-plane meant that aircraft could be used to rescue people but was limited as they could not land or take off in heavy seas.

Helicopters overcame this problem as they were able to hover over the victim and give aid by dropping a line to them with either a basket or diver to assist their extraction.

Sea

Many types of boats and ships are used, ranging from 2 man inflatables, such as the IRB

Inflatable Rescue Boat

Inflatable Rescue Boats have been used for all forms of surf rescue, retrieval, and service by Surf Lifesaving in New Zealand and Australia since the late 1980s.-Overview:...

's, through RHIB's all the way up to larger purpose built vessels.

For offshore and far from coast rescues operations most countries rely on Naval or Coastguard ships for these operations

For submarines which have got into difficulty there are highly specialised rescue submarines and support ships such as the NATO NSRS

Nato Submarine Rescue System

The NATO Submarine Rescue System is a multi-national project to develop an international submarine rescue system. The system will provide a rescue capability primarily to the partner nations of France, Norway and the UK but also to NATO and allied nations.The NSRS is managed by Rolls-Royce and...

 and the USA's DSRV

Deep Submergence Rescue Vehicle

A Deep Submergence Rescue Vehicle is a type of Deep Submergence Vehicle used for rescue of downed submarines and clandestine missions. While DSRV is the term most often used by the United States Navy other nations have different designations for their vehicles.- Chinese models :The People's...

Inland or shallow water

There are still smaller boats which may be used on inland waters such as lakes or estuaries where the waters are generally calmer and shallow. These boats are often hand powered.