When you fly into an eastern Caribbean
country, they ask you where you will be staying and for how long. If you say, "on a charter
boat (or in a hotel), for two weeks", that's the end of it--no need to produce a return flight ticket. The airline may have a problem with you if you only have a one-way ticket. They can get into trouble with the local authorities for depositing you on their shores with no visible means of departing. You'll need a convincing explanation for why your ticket is only one way.
The same applies if you arrive on a sailboat. The captain
is responsible for clearing you in, and he's responsible for making sure you will be leaving before the end of your visa period. If the captain
tells the immigration officer when he clears in the crew, " Crew A & B will be leaving the boat", the questions will start. If you, as crew, don't have a berth on another boat or a legitimate hotel
or private house to stay in, and an airline ticket to somewhere else, you may not be allowed to clear in. If you can show proof of financial resources sufficient to buy a ticket out, that might work. Or they might require you to go buy a ticket, right then and there. Or they may simply refuse to admit you.
The only times I've been in a similar situation is when I cleared in to the BVI after a passage
from the States. My crew was leaving the boat and flying home. I was required to bring their passports and plane tickets back to the States
& Immigration, and they inspected them carefully. Also, when I have had crew joining me in the islands to sail back to the States, I've always provided the crew members with a letter stating that when they arrived (with a one way plane ticket) I would be responsible for getting them off the island, on my boat.
As far as how long you can stay, I never tested the limit as we cruised, because we always moved on after a week or two or three. But here on Nevis
, where I live now and which has immigration policies that I believe are similar to other English
heritage islands, you can get a visitor's visa for a maximum
of 30 days, whether you enter by plane or by boat. If by plane, it's free (you pay at departure). If by boat it's about US$12 for all onboard.
Before the end of the 30 days, you must apply for an extension at the government
admin office. They will grant up to 90 days extension, but only if
you have a good reason. We did, because we own a home here, our only home. It costs about US$65. You then have to take the paperwork to the police station, where they check your passport and stamp it with the visa extension. The first time we did this, we were required to have a personal interview with the police chief. If you want to stay longer than the typical tourist, they really want to know why, where you'll be living, whether you have means of support, and if you intend to try to work on the island. After the second 90 day visa extension, we were required to physically leave the island for at least a few days before returning. Then the cycle starts over.
Others may have had different experiences, but this is what I've experienced and learned about the topic here in the Lesser Antilles. I'd suspect that SV & G has similar requirements.