Trim = optimum tracking, glide with least amount of drag = maximum efficiency.
Some stand up paddle boards trim flat whilst others can be railed on an edge (think slightly leaning over). Some like to be paddled from the front, with the tail slightly raised, whilst others prefer an elevated nose and engaged rear. The best thing to do is experiment and find what works best for your board (inflatables too) as every SUP is different.
The biggest thing to consider with trim is your paddle stroke, or rather how inaccurate board trim affects paddle strokes negatively. If your SUP isn’t travelling at maximum efficiency through the water then you’re essentially putting WAY more effort into each stroke and expending more energy quicker. And this goes for just recreational pootling as well as putting the hammer down. In some cases unnecessary upper board paddle work can start to aggravate – especially if you SUP regularly. This wear and tear can ultimately lead to injury, in some cases severe damage such as rotator cuff problems. There can be other contributing factors as well, such as paddle shafts which are too long, but inefficient board trim can certainly be a culprit. On top of this, if simply getting from point A to B becomes too arduous then the enjoyment of paddling slowly wanes and in time you feel inclined to SUP less and less. With temperatures still warm (air and water) it’s an idea to have a play with your board’s trim and discover what works best. Even inexperienced SUPers will find improved performance by altering your stance slightly. And in the long this’ll benefit your overall paddling as well.