What Keelshare computes, and what it leaves to you

One private link

Opening a partnership gives it a 20-character key in its link. Share the link with your partners. Anyone holding it can see and change the partnership, so treat it like a house key. We store only a SHA-256 hash of the key: we cannot look a partnership up for you, and a lost link cannot be recovered. A partnership nobody opens for 400 days is deleted.

Turns

A turn is one partner's run of days, from 1 to 14 days. One boat can only be in one place, so a turn that overlaps another is refused and the clash is named.

The fair rotation draft

Give the season's first and last day. Keelshare lists every weekend (a Saturday whose Sunday falls in the season) and deals them:

1. The holiday weekends that fall inside the season are dealt first, one each: Memorial Day (Saturday to Monday), the weekend nearest July 4 (stretched to include the 4th when it falls on a Friday, Sunday or Monday), and Labor Day (Saturday to Monday). The dealing order is the partners in their listed order, moved one place every calendar year, so nobody keeps the same holiday.
2. Every other weekend, in date order, goes to the partner with the highest share ÷ (2 × weekends so far + 1). This is the Sainte-Laguë method used to share out seats in proportion to votes; here it shares weekends in proportion to ownership.

The draft shows what each partner is entitled to (share × weekends) beside what they were dealt. Applying it writes each drafted weekend into the calendar, skipping any that clash with turns already there. Weekdays stay first come, first served.

Engine hours

Each line is a day, a partner, the engine hours run (0.1 to 48) and, if you like, the fuel added. Hours are totalled per partner per calendar year. Keelshare does not read any meter or track the boat.

Money

Each cost has who paid it and how it splits:

• By shares: in proportion to ownership, as the shares stood when the cost was entered.
• By engine hours this year: in proportion to the hours each partner logged in the cost's calendar year, worked out again as hours are added. With no hours logged that year it splits by shares, and the ledger says so.
• Equally, or all to one partner.

Splits are exact to the cent: each partner gets their exact part rounded down, and the cents left over go one at a time to the largest remainders. A partner's balance is what they paid, minus their part, plus transfers they sent, minus transfers they received. Balances always add up to zero.

Settle-up finds the fewest payments that clear everything. It first looks for partners whose balances cancel out among themselves and settles each such group on its own, then pairs the largest debt with the largest credit inside each group. That is never more than one payment fewer than the number of partners, and often less. In the example on the home page, Cal pays Ana $375.00 and Ben pays Ana $75.00.

What it is not

Keelshare is not a bank, an escrow or a payment service: it holds and moves no money. It is not a maintenance schedule, a booking service for a marina or a club, and not a legal agreement. The checklist lists what partners commonly settle in writing.