This applies to the Mac only. On iPhone or iPad, the tools work the same on all devices.
It was originally envisioned that sailors who are using LuckGrib at sea would be using laptop Mac’s which have large touch pad’s. Using the touchpad to navigate around the map and use the tools is pretty intuitive, and works as documented. Scrolling is done with the two finger scoll gesture, and zooming is through pinch and expand gesture. Clicks on the touchpad interact with the tool.
There are two main types of mice that can be used with a Mac: the Apple Magic Mouse and a third party scrolling mouse.
One of the most important actions that you must be able to do easily is to navigate around the map: scroll and zoom. When using a mouse, scrolling is done by clicking on the map and dragging. On a magic mouse you can scroll on the top of the mouse to perform a zoom (in or out.) On third party mice you can use the scroll wheel to perform a zoom.
This leaves the question of how do you interact with a tool when using a mouse? The tools (Pan, Recctangle, Measure Line, Points and Routes, Weather Routing) each allow you to click on things to perform actions. For example, click on the map to create a point, click on a point to move it around, click on something to bring up a menu, and so on.
To perform the clicking action on a mouse, use its secondary click. This is usually a click on the right side of the mouse, although this can be configured in the Apple system settings in the mouse category to move the secondary click to the left side, or turn it even to turn it off.
So when you read, in the manual, to perform a “click” on the Mac, use this secondary click action.
You will probably be able to discover how this works yourself through a little experimentation. You can’t break anything, click around and give it a try!