Countries became independent in order to promote self-reliance and independence. This requires the accumulation of sovereign national wealth in order to build sea ports, airports, bridges, roads, railways and so on and so forth.
Unfortunately for Africa, many countries rely on investors to take ownership of large chunks of their lands and waters to build assets that will ultimately be controlled by foreign investors. Such investors will sign agreements with governments that will require international arbitration to resolve conflicts. In many cases countries have to pay huge sums of money for damages that come from rulings by international tribunals.
Gambian authorities should do proper evaluation of what could be gained in the long run by allowing huge portions of their land and beaches to fall in the hands of external investors.