You run the club's trips. Mixed certs, a boat to charter, deposits to chase, and a committee that wants a say. Manta turns the whole expedition into one plan every member can see - and pay their share of.

Hold the boat, count the bunks, and let members claim their spot before the trip fills up.
Open Water through Tec. See who's qualified for what, so nobody's signed up for a dive they can't do.
Split the charter fairly per diver, see who's paid the deposit, and chase the stragglers without nagging.
Float a few windows around the season, let members vote, and lock the week the most divers can make.
Manta was built for exactly this: a club where every diver wants a slightly different trip, on one boat, with one organiser chasing it all. Members join by link, claim a bunk, log their cert level, vote on dates, and the expedition comes together. You stop being the dive-trip secretary.
Booking stays off-platform and fair: pick the liveaboard and the day boats, split the cost per diver, and book with the operator directly. We never touch your money.
Pick a base - each links to its full guide.
Add a thing to do - each links to its activity guide.