FYI ... for those who think you don't really need tab indicators might consider them for this use ...
"If" you run a fuel computer, you will find out very quickly that running the trim tabs at their most efficient hull angle-of-attack can create benefit GAINS of up to 20% in fuel efficiency over "not" running any trim tabs. But, when 'over'-tabbed, you can also seriously CUT your efficiency up to 20%.
Since I do run a fuel computer, I find that the tab indicators provide me with 'what number' is giving me the best ride AND performance efficiency in miles-per-gallon, as you'll quickly learn from the sea state that day. Then if/when I'm running/gunning and stopping to fish or troll, I can simply dial it right back in when up on plane again, given the same conditions.
This works out so well for me that I am strongly considering the Bennett Auto Tab mechanism that uses an artifical horizon to automatically keep the boat on the same angle of attack, regardless of the boat's speed and directions into the sea state.