とんたとんたさん　へ

本日、コモ湖ボートインフォからわざわざ英文で回答メールを受け取りました。

Small size dogs (not over 50 cm. of lenght) taken onto vessels (including hydrofoil and catamarans) have to be kept on a leash but can also stay without muzzle only if the owner holds them on his knees or in his arms. Medium and big-size dogs taken onto vessels (excluding hydrofoil and catamarans) must always be kept muzzled and on a short leash. None of the animals can occupy a seat and must be put in condition not to disturb other passengers.

For each dog admitted to the transport you will have to buy a ticket at the children's fare.

とんたとんたさんのイタリア語訳と同じです。
コートダジュールのホテルを全部キャンセルしてミラノまでの飛行機便（犬キャビン）・レンタカー・コモ湖周辺ホテルの予約を取りました。
いろいろありがとうございました。