• 18 parts
  • Checked September 2026

Parts of a Catamaran

A sailing catamaran from above, from the side and from the front.

Parts of a Catamaran

Name Date

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
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Write the name of each numbered part.Answer key

  1. Starboard hull
  2. Port hull
  3. Bows
  4. Transoms
  5. Trampoline
  6. Front crossbar
  7. Rear crossbar
  8. Tiller crossbar
  9. Mast
  10. Boom
  11. Mainsail
  12. Battens
  13. Jib
  14. Forestay
  15. Rudders
  16. Dolphin striker
  17. Shrouds
  18. Daggerboards

Drawn for this site on 2026-09-30 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a part is answered.

Next step Next: one hull and a keel, the parts of a sailboat

All 18 parts on the diagram

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Hulls and platform 9

  1. Starboard hull A catamaran has two parallel hulls of equal size. Starboard is the right side of a boat, facing forward.
  2. Port hull The wide gap between the two hulls keeps a catamaran upright. It carries no ballast.
  3. Bows The wires that hold the forestay are made fast to them.
  4. Transoms A rudder hangs on each transom.
  5. Trampoline It is the boat's deck, laced tight to the frame.
  6. Front crossbar The mast is stepped on the middle of the front crossbar.
  7. Rear crossbar The rear crossbar closes the frame behind the trampoline.
  8. Tiller crossbar Each rudder has a short tiller. The crossbar connects the two.
  9. Dolphin striker It helps the crossbar carry the downward push of the mast.

Mast, sails and wires 7

  1. Mast On most beach catamarans the mast can rotate.
  2. Boom A boom is a spar attached to the foot of a sail.
  3. Mainsail On most beach catamarans the mainsail has full-length battens.
  4. Battens A batten is a stiff strip that supports the sail. Full-length battens run right across it.
  5. Jib The jib is set on the forestay.
  6. Forestay On a catamaran it ends above the water. Bridle wires tie it to the two bows.
  7. Shrouds One shroud runs from the mast down to each hull.

Rudders and daggerboards 2

  1. Rudders There is one on each transom. They kick up when they touch the bottom.
  2. Daggerboards A daggerboard counters the sideways push of the sail. It slides in a casing and can be pulled up.

How this list was compiled: Every name checked on 2026-09-30 against two independent sources, a name kept only where both use it. (1) A maker's manual and parts guide: Hobie 18 SE/SX Assembly Manual, full text at https://archive.org/details/manualsbase-id-554641 (port hull, starboard hull, front and rear cross bar, tiller cross bar, trampoline, dolphin striker, rudders, daggerboards, mast, boom, main sail, jib, battens, shrouds, forestay, bridle wires), with the Hobie Cat sailing parts catalog, https://archive.org/details/manualzz-id-1070992. (2) Wikipedia, text only: Catamaran, Hobie Cat, Hobie 16, Hobie 18, Dolphin striker, Daggerboard, Forestay and the Glossary of nautical terms (boom, jib, batten, shroud, starboard). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's boat, nothing traced. Licence: own work

How it works

The parts of a catamaran, shown on a small sailing catamaran of the kind launched from a beach. Three views: from above with the sails off, from the side, and from the front.

Read the full guide

The platform

A catamaran has two parallel hulls of equal size. Two crossbars join them, one at the front and one at the back, and a trampoline is laced between the bars and the hulls. The mast stands on the front crossbar, and under that bar a post and rod called the dolphin striker help carry the mast's load.

Two of everything under water

Each hull has its own rudder, hung on the transom, and the tiller crossbar links the two so they turn together. Many catamarans also have a daggerboard in each hull, which slides down through the hull into the water.

  • Port and starboard are judged facing the bows: port is on your left, starboard on your right.
  • A catamaran carries no ballast: the wide gap between its hulls keeps it upright.

Questions and answers

What are the two hulls of a catamaran called?

The port hull and the starboard hull. Facing the bows, the port hull is on the left and the starboard hull on the right. The two are parallel and the same size.

What is the net on a catamaran called?

The trampoline. It is a deck of stretched fabric, laced tight between the crossbars and the two hulls.

What is a dolphin striker on a catamaran?

A short post with a tensioned rod under the front crossbar. The mast stands on that crossbar, and the dolphin striker helps the bar carry the downward push of the mast.

Do catamarans have daggerboards?

Some do: a daggerboard in each hull slides down through the hull to counter the sideways push of the sails. Others, like the Hobie 16, have hulls shaped to work without daggerboards, so the boat can be run up a beach.

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