There are still only very limited connections to the island by air, and no passenger travel by sea, as yet. Potential travellers will need to check carefully any current pre-departure requirements in their home jurisdiction, and whether any public health requirements will apply on their return home. You will also be obliged to follow in-transit requirements stipulated by your carrier.
If you travel to the Bailiwick by plane you will be given a mask to wear whilst on the plane. Full details can be found here: https://covid19.gov.gg/guidance/travel