Sailing tools and honest gear takes. For coastal cruisers, lake racers, and anyone whose boat doesn't have a chartplotter that does all this for them.
The sailing internet is mostly two extremes. YouTubers cruising the Mediterranean on $400k catamarans, or "learn to sail" content for absolute beginners. Middle-ground content for the cruiser anchoring in the Chesapeake for the weekend is harder to find.
These tools live in the middle. Apparent wind. Anchor scope with tidal range. Sail-to-displacement ratio for when you're shopping. Nothing fancy.
Tools
Apparent Wind Calculator
Convert true wind and boat speed into apparent wind angle and speed. The number on your wind instrument vs. the wind that's actually in the sails.
Anchor Scope Calculator soon
Required rode length by water depth, tidal range, and chain-to-rope ratio. The 7:1 rule oversimplified; this gives the honest answer for mixed rode.
Sail Area to Displacement Ratio soon
Quick math for buying a used boat. SA/D, displacement-to-length, comfort ratio in one panel.
Plain note about money: Some product links are affiliate (eBay Partner Network). Small commission on purchases. Doesn't change your price. Reviews come from actual boat-time. Lewmar still makes a better winch than the cheap alternatives, but you might not need a winch.