OOC: Because it's always needed.
Folks, so you know, simply base don Crafting rules, you're going to need a week for Jaseena to build the raft. No reason not to forage for supplies every day, of course, if you can see well enough. We can stop once you have enough water barrels and the Helm, but, until then, you may find other things, so we'll keep going for now.
Whether you take a second week for a bigger raft we'll address at the end of Day 7.
Without a 5th level cleric to Create Food (or food and water producing magic items), there is a resource management issue to a Spelljammer game.