How much to call home using my phone?

If you are using your own phone on roaming this is likely to be significant and you should check rates with your provider. Using the local mobile Horizon Yacht Charters provide, current charges are around US$0.45 per minute to the USA, £0.39 to the UK, CAD 0.58 to Canada and € 0.40 per minute to the rest of the world (rates correct as of Jan 2020).