There are certain things that we get accustomed to. Heinz ketchup can't be replaced by anything else. Barbecue sauce, on the other hand, is an ongoing experiment, and there are some excellent local brands. Mustard, well, with two or three different kinds on board, something will work out just fine, and the French certainly have the selection when it comes to moutarde.
We (Ken) has a strong preference for one kind of rum to mix with his Diet Coke (we have found that there are some acceptable alternatives to the real D.C. for our taste buds). That rum is from Grenada, but there are some other ones that are quite acceptable substitutes that are produced on other islands. This isn't high end stuff, just decent plonk that goes well with Ken's sundowner of choice (I am much more flexible, partly because migraines are not a concern for me). However, in the French islands, they make their rhum a little differently, and it has a huge impact on the flavour of the rhum (rum). It doesn't mix particularly well with Diet Coke. There are some great aged sipping rums, depending on your preferences, and the unaged rhums are well matched for a ti ponche or planter's punch, but finding something that works well with coke is a bit of a challenge. However, we are taste testing in the occasional bar to see if we can find something acceptable, since we aren't in a rush to leave Guadeloupe, and our supply is getting very low.
Peanut butter is another concern altogether. The French don't "do" PB. Lord knows that if it has chocolate in it, they have a thousand different ways to consume it, but not peanut butter. And PB is a staple on our boat. A spoonful with a banana before a long run is excellent fuel for me, and sometimes it is that needed kick in the middle of the day. There is something sublime about a PB&B sandwich at times. We have found it in the supermarkets, but a small jar is quite expensive, and not always a good quality peanut butter, either. We are experimenting with generic Nutella type spreads as an alternative; surprisingly, less fat, but also far less protein, which is one of the benefits of peanut butter. However, chocolate spread with some salted peanuts makes a pretty tasty combo. I am trying to ration my consumption of PB as much as possible. We have a friend flying down to visit... I've asked her to bring peanut butter.
Thankfully, we have plenty of Heinz ketchup in the bilge. The rest, well, we will have to find a compromise while we are here. And I've given up on almond butter, unless I want to consume something that is almost worth its weight in gold down here (and the French don't have that, either).