łódki

In a sentence

• Na jeziorze pływa wiele łódek.

  There are many boats floating on the lake.

  This uses 'łódek' (plural of 'łódka') in its plural form, indicating multiple items (boats) located on the lake.

• Lubisz łódki czy kajaki?

  Do you prefer boats or kayaks?

  Here, 'łódki' is used in nominative plural as part of a question contrasting different types of watercraft.

• Miło jest spędzać czas na łódce.

  It's nice to spend time on the boat.

  In this case, 'łódce' (singular form in the locative case of 'łódka') is employed showing the singular item in a specific location (on the boat).