You may need an embassy visa for Martinique if you have a Dominica passport
Visa options for Martinique
Visitor visa is required for trips longer than 15 days
Travellers need a visa to visit Martinique for Business or Tourism for more than 15 days. Travellers do not need a visa if staying for 15 days or less, with a limit of 120 days over 12 months. A paper or embassy visa is the only visa available for travellers visiting Martinique for more than 15 days. The visa is typically a stamp or sticker added to the passport. Travellers must obtain this visa from a local embassy, consulate or visa center before travelling.
This is not offered by sherpa°.
Apply on the government site.