The Harbor Column:

Our warm boating weather will take a slight change of course this weekend with cooler temperatures and the chance of showers.

The weather system will cause the Pacific swells off Newport to build up to 6-feet and tapering off to more than 3-feet by Monday.

If the rains hold off, sailing inside the harbor will be good, as the winds are expected to reach Force 5 on Saturday before dropping to Force 3 on Sunday.

“Force what?”

The Beaufort Scale of Wind Force was developed in 1805 by Adm. Sir Francis Beaufort as he would determine the wind force by conditions of the seas.

For example, if the ocean had small wavelets with glassy-appearing crests, then he called that a light breeze of 4 to 6 knots, and a Force 2.

If the high wave had crests break into spindrifts with foam, then he figured winds were blowing 34 to 40 knots, creating a Force 8. You get the picture. The scale goes from Force Zero, dead calm, to a Force 12, a deadly hurricane.

I do not use his scale because I would have to memorize 12 wind categories that are realistically used in only some sailing circles today. However, I use my own unofficial Whitehead Scale, which does not use a numeric scale, but a pain and able-to-eat-a-meal scale when aboard a boat. As such, flat seas imply a calm, no-pain voyage where we can sit down to eat a meal on a plate.

However, swells of 5- to 7-feet with 20-knot winds mean some bumping and yawing of the vessel, causing mild pain, and you must eat finger foods while bracing yourself in your helm seat. Larger swells, especially with stronger winds, indicate pain that may take a couple of days to recover from, and the vessel is being tossed around, pounding off the tops of the swells.

Additionally, you are lucky to hit your mouth with any food in these conditions.

Most of the time I hear boaters using my unofficial Whitehead Scale versus formal Beaufort Scale when chatting about their recent voyage, and I have noticed that the pain scale keeps increasing with each reiteration of the story or the next serving of drinks.

MIKE WHITEHEAD is the Pilot’s boating columnist. Send marine-related thoughts and story suggestions to [email protected] or go to www.boathousetv.com .