The marine park consists of a 1,400-acre (5.7 km2) sand-bottom lagoon which encompasses the five cays, the inhabited island of Mayreau and the 4 km Horseshoe Reef.

[1] The most extensive and well-developed coral reef complexes in Saint Vincent and the Grenadines occur on shallow shelves around the windward sides of Mayreau and Union islands and the cays themselves.

The Grenadines are geologically older than St. Vincent and are situated on an extensive shallow bank of volcanic origin – known as the southern Lesser Antilles arc platform (SLAAP).

The terrestrial flora consists mainly of dry forest, grasses and shrubs, including species such as coconut, agave, cactus, Coccoloba sp.

In the Tobago Cays Marine Park, highly poisonous manchineel trees (Hippomane mancinella) are well established on Petit Rameau, Baradal, and Jamesby islands.

This led to a detailed proposal for the formation of a Tobago Cays National Park with initial investment costs estimated at US$1 million.

In September 1993 (as described by Espeut, 2006), the governments of France and St. Vincent and the Grenadines signed and launched the Tobago Cays Marine Park Project and produced an updated action plan (FMC, 1995).

In November 2001, a study by Caribbean marine park manager, Tom van't Hof (ECLAC, 2002), described the slow progress with implementation up to this time and outlined some of the problems.

With legal discrepancies in the appointment of its members, the board ceased to operate in 2001, and French financial assistance to the park was discontinued at the end of that year.

In May 2003, it was announced that the Government was considering a proposal for the day-to-day management of the Tobago Cays to be contracted to the nearby but foreign-owned Palm Island Resort.

The plan would have seen several structures erected on the islands and the concept of handing a prized national asset to a private company caused a public outcry.

In September 2003, a local NGO – the Mayreau Environmental Development Organization (MEDO) – then submitted a counter-proposal to the Marine Parks Board.

The June 2, 2003 plan by Palm Island Resort Limited (PIRL) for the management of the Tobago Cays clearly offended the public, including those in the southern Grenadines.

The PIRL proposal had in fact violated parts of an earlier agreement to return the Tobago Cays from private investor ownership to the government of St. Vincent and the Grenadines, a deal made under the auspices of the Multilateral Investment Guarantee Agency (U.I.G.A.).

The June 10–11, 1998 round of negotiations in Barbados formed the basis for Prime Minister Mitchell's public statement on this matter a year later.

"I wish to warn that my government fully understands that should we ever entertain or engage or permit commercial activity in Tobago Cays we are creating opportunity for the original owners to re-open their claim for US $6.5 million plus interest accruing from today".

The PIRL management proposal held no real benefits to local stakeholders, including those in the diving, yachting and day excursion industries.

Concern over PIRL proposals cemented the formation of the Alliance of Union Island Environmental Organizations, which in turn approached other Vincentians for assistance.

The Friends of the Tobago Cays (FOTC) had as its core element some members of the defunct National Trust of St. Vincent and the Grenadines and emerged as the organization that would bring the issues to the public's attention.

The FOTC took up the challenge and embarked on an education program aimed at demonstrating the folly in handing over the management of the cays to a foreign private operator.

After critiquing the management plans of the PIRL, the FOTC expressed concerns in respect of (a) maintaining the integrity of our cultural and natural heritage; (b) financial arrangements; (c) the legal implications of commercial activity in the Tobago Cays; and (d) the handing over of regulatory functions of government to a private entity.

The FOTC's proceeded to conduct meetings with various stakeholders, including those in the Grenadines, the Government, Service Clubs and the Chamber of Industry and Commerce.

The government chided the critics of PIRL Management Proposal as "a small minority of Vincentians" who were at the same time accused of being "dishonest, vindictive, untruthful and malignant".

The current arrangement lacks local involvement in decision making and gives too much responsibility to the board for operational matters rather than policy issues and national coordination.

Despite being described in various sources as one of the largest remaining pristine coral reef groups in the Windward Island, there is growing evidence that this ecosystem is being affected by non-sustainable use and natural environmental impacts.

Visitation is difficult to control due to number of boats (many of which are under an international flag) exacerbated by the absence of regular coast guard patrols.

Major stakeholder groups include "boat boys" (locals who service the visiting yachts); diver and hotel operators; and the fishers.

There appears to be a growing perception among many of the locals that despite the increasing number of tourists and the presence of a world-class resource, they are not benefiting from the development area.

There are a number of vendors in the park, selling T-shirts, handicrafts, ice, bread, fresh fish, fruits and vegetables to the visiting yachts.

The WWF-World Bank Alliance's Scorecard to Assess Progress in Achieving Management Effectiveness Goals for MPAs adapted for PAs of the OECS.