It's been years since I've played.  I have a clue scroll (do they even do those anymore?) that requires navigation.  I have a sextant, watch, and chart in my tool belt.  But when I try to use it, it tells me that I need one first.  How do I use the sextant in my tool belt?

Moved to Help & Advice.

But I'm confused as to what you mean exactly. When you try to use what, exactly? And it tells you need what? I would highly recommend using our coordinates guide or RSwiki's Coord guide, and just go straight to the location and digging at the spot, instead of trying to figured out the sextant.

Also, are you absolutely 100% certain you have the chart, sextant and watch in your toolbelt, as well as the clue in your inventory?