Go or no-go: habits for small boats and RIBs

A Navigate Boats guide · Updated 4 November 2026

There is no single official knot value at which every small boat on the Adriatic should stay in harbour. A heavy boat and a light RIB are not the same, a boat with children aboard is not the same as a boat without them, and a wind that is fine in a lee is not fine on an open crossing. Anyone who gives you one number for all of them has invented it. This page does not. It describes the habits that keep a small boat out of trouble, and it points at the services that are allowed to issue warnings.

What the board is doing

The live board takes the forecast and your setup: the type of boat, the size, and whether children are aboard. It looks at the wind, the gusts and the wave height, and it turns that into a go, a caution or a stay-in for that boat. Smaller boats and boats with children are judged more tightly. That is a planning aid, not a regulation and not a substitute for the skipper. If you change the boat in the setup, the verdict is allowed to change. That is the product working.

In Croatia the board also reads DHMZ wind warnings. A yellow, orange or red warning for the area puts a floor under the verdict: the page will not tell you the day is better than the warning allows. The warning is the official document. The board is only refusing to talk over it. Read the warning itself on meteo.hr.

Habits that are not a number

Read gusts, not only the mean. The Bura is the wind that punishes people who skip this. A moderate average with a much higher gust is a gust day.
Read the sea as well as the wind. The Jugo builds a sea along the length of the Adriatic. A modest wind can still be too much sea for an open boat. The forecast guide explains the numbers.
Decide the way home first. The Maestral is often stronger in the afternoon than in the morning. A trip that is easy outbound can be the wrong trip back. If you would not like the return, do not leave.
Stay in a real lee. The lee of an island breaks the wind and the fetch. The lee of high ground can still have sudden downdrafts. A bay that faces the wind is not a lee, however pretty it was yesterday.
Leave a margin. A forecast that strengthens at four is not an invitation to be out at four. Thunderstorms on a summer afternoon arrive faster than a small boat covers the last mile.
One doubtful sign is enough. A warning, a gust forecast you do not like, a sea that is already up, or a board that says stay in. You do not need all of them.

What this is not

It is not a statement of Croatian, Slovenian or Montenegrin law. Speed limits, protected zones and park rules are whatever the current official text says, and they change. Park fees are on each park’s own site. The park guide points at those sites and does not keep a price list. Weather warnings are DHMZ in Croatia and ARSO in Slovenia. In Montenegro use the national hydrometeorological service. If this page and those services ever differ, follow the services.

A short way to use the morning

Read the official forecast and any warning. Set the boat you actually have, including the children if they are coming. Look at the board for the hour you would leave and the hour you would come back. Look at the gust and the wave, not only the pretty number. If the return is the problem, change the plan, not the definition of a safe day. Then go, or do not.

Check today’s go/no-go for your boat

These guides describe typical patterns, not today’s weather. Navigate Boats is a planning aid, not a navigation tool: before you go, check the official marine forecast and warnings from DHMZ (Croatia), ARSO (Slovenia) or the Montenegrin hydrometeorological service, and use your own judgement.

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