Honey get the earplugs.

[jackytdunaway]

I just got to work from two nights on the lake anchored off an island. Great sailing during the day. Cool breeze at night for good sleeping. The only bad part about it is the constant slap on the inside of the mast. i think all the electrical wiring is in sleeves and it sounds more like lines slapping the inside of the mast. Any ideas on how to combat this. i tried tightening and loosening lines to no avail. It is like sleeping on the inside of a guitar.

[Faster]

If changing the tension of your halyards/topping lifts etc doesn't affect the noise, then in all likelihood you have at least one unsecured wire inside the mast. Someone may have added some equipment at some point and simply dropped the cable down the stick.

You don't say what boat/mast arrangement it is, but if you can get at the wiring at the mast base, see if any particular wire seems looser than the others. It may be the culprit.

Also if you have halyard exit slots, maybe try to look inside with a small flashlight (at night probably easiest - with a dentist mirror?) to see if you can spot the noisy bugger.

This sort of thing can drive you nuts!

[petegingras]

Some masts have an internal conduit which protects and house the wires. Often times these conduits are "pop" riveted to the mast, you'll notice the rivets running inline up the mast. It’s possible one or more of the rivets have corroded and fallen loose; if so pop rivets are easily enough replaced.

If you’re without a conduit the wires are running free, you can either secure them by drilling into the mast and securing the with (not my recommendation) wire ties. Or drill holes every 8-10 feet up the mast and insert expanding foam (like the foam used to insulate doors and windows in the home: GreatStuff®) which will secure the wires at those intervals, but you’ll never run anything internally up that mast again (and this is out of the question if you’ve got internal halyards. Finally the correct way would be to unstep the mast and run a new conduit. And the right way is the most expensive, but the other ways will also appease your dock & mooringmates.