Sailing Outing RSVP Website: Berth Counts, a Crew Cap, and a Swim Line
A sailing outing RSVP has to lock a berth and a crew spot before the lines come off, because a maybe does not hold a berth.

A sailing outing breaks when the boat has six guest berths and nine people are on the dock, or when someone who said maybe arrives after the lines are off and expects a spot the harbor already counted. Berths, the crew cap the charter will take, and the swim line you agreed to are set before the first line comes off the cleat. The skipper does not add a body because a friend decided to come after the manifest closed. A maybe does not hold a berth.
You can create a sailing outing RSVP that fills the berths the charter will take, records who can be on that boat, and stops when the manifest is full.
Ask what the charter will actually take
Call the charter before you send the link. Write down the boat, how many guests that boat holds besides the skipper, how long the sail is, whether a life jacket is on board for every guest, the shoe rule, and whether a swim stop is even offered. Those numbers are your cap. Do not guess from the length of the dock.
A berth is one person, not one couple and not one car. Ask whether a child still needs a full berth, the age minimum, and whether a second boat uses a different slip and a different cap. Pick one boat and write it on the page. If you are splitting the group across two boats, those are two lists with two caps. Do not mix them and sort people out on the dock.
Ask the price, the minimum guest count that keeps the private booking, and the last time you can cut the count before they release the boat to the public list. If they charge for a no-show after that time, or if dropping under the minimum cancels the private, print that rule on the page.
Set a capacity limit on people who will be on the boat, not on everyone who was invited. When the last berth is taken, the form should say the outing is full. A friend who might come still needs a berth and a life jacket the charter counted. If the harbor has already counted your group, they are not on this boat.
The swim line is a yes or a no, not a vibe
Ask the charter what the sail includes: deck only, or a swim stop if the skipper calls the water safe. Put that on the page in plain words. Each person confirms they will stay on deck, or they confirm they may swim if a stop happens. A life jacket is not optional either way. Write that next to the question.
If the charter will not stop to swim, say that. People who only want a swim day should not take a berth on a deck-only sail. You do not need a swimming resume. You need a yes or a no before the manifest is sent. A hope that the skipper will change the plan should not be on the form.
A step down, a dock, and a tide that does not wait
Most days start on a dock that may have a ramp and a boat with a step down into the cockpit. Ask about access needs the boat can actually meet: a ramp to the slip if one exists, or a clear note that the only way aboard is a step. If there is no head, or the head is down a companionway, say that.
Ask the wind number or small-craft rule that cancels the day. Put a weather contingency on the page that matches the charter, not a guess from a phone app. If they cancel over their number, the berth is released and nobody is owed a different boat unless they offered one. The arrival window might be 9:10 to 9:20 at the slip they named. Write the clock time and what happens if someone is later than that: the boat leaves for the tide, and a late guest does not get a berth back. If the charter requires soft-soled shoes, write that too.
The moment the manifest is locked
The meeting point is the slip the charter assigned you, with the marina name if there is more than one gate. Put the host's phone on the page for the person holding the reservation. A screenshot of the invite is not a berth. The skipper matches names to the count you sent.
If you allow a guest, that person needs their own berth line, their own swim answer, and their own arrival window. Track them as a separate yes. One form that hides an extra body will blow the charter's cap and the life-jacket count. Say that on the page. Children count if the charter said they need a berth. Write the age rule next to the question.
Tie your RSVP deadline to the charter's final count, the day they lock the manifest or release the boat. After that, a late yes is a call about a cancellation, not a promise of another berth. If you want names ready when someone drops, keep them as standbys and tell them they do not have a berth until you write back. A maybe does not hold a berth.
Export the list the morning you lock: attending or not, deck only or swim if offered, party size, arrival window, the access note the charter agreed to, and phone. A sailing RSVP is finished when every berth has a named person, the swim line matches a stop the skipper might actually make, and a late car knows whether they are aboard or going home.