Ym mis Awst, wrth i'r haul ysblennydd ddisgleirio dros Draeth Heulog, roedd Cariad a Tesni yn barod i ddechrau eu trip ysgol.

In August, as the splendid sun shone over Sunny Beach, Cariad and Tesni were ready to start their school trip.

Roedd y diwrnod yn braf a'r traeth yn edrych fel rhan o baradwys - tywod euraidd, dŵr clir, a chlogwyni gwyrddlas o gwmpas.

The day was fine, and the beach looked like part of paradise - golden sand, clear water, and green cliffs around.

Roedd mor braf yma fel y byddai unrhyw un yn teimlo eu bod ar wyliau.

It was so pleasant here that anyone would feel like they were on holiday.

Ond nid gwyliau oedd hyn, roedd yn drip ysgol.

But this was not a holiday; it was a school trip.

Cariad, gyda'i gwallt melyn a llygaid glas, oedd y ferch mwyaf chwilfrydig yn y dosbarth.

Cariad, with her blonde hair and blue eyes, was the most curious girl in the class.

Roed hi wastad yn darllen llyfrau am fioleg y môr, ac am bysgod, crancod, a phopeth arall yn y dŵr.

She was always reading books about marine biology, and about fish, crabs, and everything else in the water.

Tesni, ei ffrind gorau, roedd yn fwy ofalus.

Tesni, her best friend, was more cautious.

Roedd hi'n ddigon hapus i ddarllen amddiffyniadau ar gyfer ecwibwynt a pharodrwydd.

She was quite happy to read about defenses for ecosystems and preparedness.

Wrth gerdded ar hyd y traeth, Cariad yn sydyn yn troi at Tesni, “Tesni, wyt ti wedi clywed am y llecyn cawraidd o dan y dŵr ger yma? Mae pawb yn sôn amdano.”

While walking along the beach, Cariad suddenly turned to Tesni, "Tesni, have you heard about the giant spot underwater near here? Everyone is talking about it."

“Ydyn,” meddai Tesni yn ofalus. “Ond mae'n beryglus iawn ac mae’r athrawon wedi dweud 'na i fynd yno.”

"Yes," said Tesni cautiously. "But it's very dangerous and the teachers said not to go there."

Cariad, yn llawn antur ac awydd, meddai, “Rydyn ni'n gallu edrych, dim ond am funud. Beth ddylet ti ddweud?”

Cariad, full of adventure and eagerness, said, "We can just look, just for a minute. What do you think?"

Tesni wnaeth dweud ynddo hi, “Cariad, mae'n beryglus iawn... Ond dw i’n dod gyda ti. Dim ond i wneud yn siŵr dy fod di'n saff.”

Tesni sighed, “Cariad, it’s very dangerous... But I’ll go with you. Just to make sure you’re safe.”

Pan aeth yr athrawon i'r sied pysgod ar gyfer y sesiwn nesaf, Cariad a Tesni gwnaeth casglu eu hofferyn nofio a llithro oddi ar y traeth yn dawel.

When the teachers went to the fish shed for the next session, Cariad and Tesni gathered their swimming gear and quietly slipped away from the beach.

Daethon nhw’n gyflym at gwch bach, wedi ei angori’n gynnil ar ymylon y dŵr.

They quickly came upon a small boat, discreetly anchored at the water’s edge.

Gydag ychydig o alebion cyflym ac atgar, nofiodd y ddau ferch at y cwch a gwibio tuag at y rhewlif tanddwr mêl.

With a few quick and encouraging glances, the two girls swam to the boat and sped towards the hidden underwater glacier.

Roedden nhw'n teimlo’r cyffro o droi cornel y traeth a gweld ceg y lecyn o'u blaenau.

They felt the thrill of turning the corner of the beach and seeing the mouth of the spot ahead of them.

Cariad a Tesni daeth o hyd i’r llecyn, a heb betruso, plymion nhw i’r dŵr oer a chlir.

Cariad and Tesni found the spot, and without hesitation, they dived into the cold, clear water.

Wrth iddo fynd yn dywyllach, aethon nhw’n bellach i'r llecyn lle roedd lleoedd o dywod euraidd ac algau uchelgeisiol.

As it got darker, they went deeper into the spot where there were patches of golden sand and ambitious algae.

Allai Cariad ddim helpu ond wenu wrth i Tesni edrych yn nerfus o'i chwmpas. “Edrych! Mor hyfryd!” gwaeddodd Cariad.

Cariad couldn’t help but smile as Tesni looked nervously around her. "Look! How lovely!" shouted Cariad.

Ond yn sydyn, clywsant som brawychus - y llanw oedd yn byrhau’r agorfa!

But suddenly, they heard a terrifying sound - the tide was closing the opening!

Tesni roedden yn teimlo ei chalon ronci. “Mae’n rhaid i ni fynd, nawr!” meddai hi’n daer.

Tesni felt her heart race. “We have to go, now!” she said urgently.

Cariad arweiniodd eu ffordd yn ôl gyda phenderfyniad.

Cariad led the way back with determination.

Wrth iddyn nhw nofio, lle'r oedd cynt ar agor, nawr roedd llif y dŵr yn ôlaf i fewn.

As they swam, where once it was open, now the water flow was narrowing in.

Wrth i'r dŵr cnuddi'w mynwes, roedd yn amlwg y rhifinnau'n cyfyngu.

As the water pulled at them, it was clear the opening was closing.

Roedd y gwarchodfa'n pwyntio cefn yn dynn erbyn pêl morol.

The sanctuary turned into a tight race against the marine current.

Gyda chyffwrdd ac undod, roedd Cariad a Tesni yn llwyddo’n ddiweddar dod o hyd i'r agorfa yn ail ac yn taflu’i hunain ato.

With touch and unity, Cariad and Tesni finally managed to find the opening again and hurled themselves towards it.

Roedden nhw'n rhydd!

They were free!

Wrth iddyn nhw bron cyrraedd ar y lan, fe welsant y naill at ei gilydd, gorau ydyn nhw, a gwenu.

As they nearly reached the shore, they looked at each other, best friends, and smiled.

Cariad, wedi dysgu gwers werthfawr am barodrwydd a perygl, aeth yn gyflym i ymddiheuro pan cyrhaeddodd yr athrawon yn bryderus.

Cariad, having learned a valuable lesson about readiness and danger, quickly went to apologize when the concerned teachers arrived.

“Pwy a feddyliodd,” meddai Tesni wedyn, “byddwn ni’n dysgu mwy am fywyd y môr... a’m bywyd ein hunain heddiw.”

“Who would have thought,” said Tesni afterward, “we would learn more about marine life... and our own life today.”

Cariad, yn gwenu’n braf, cyffyrddodd llaw Tesni’n barchus diolch.

Cariad, smiling brightly, touched Tesni’s hand respectfully in thanks.

Gyda'r haul yn aros gwenu arnynt, dylen nhw bellach dysgu gwersi ychwanegol, dilyn rheolau ond hefyd archwilio gyda chynllun a pharaniad.

With the sun continuing to smile upon them, they now had extra lessons to learn, follow the rules but also explore with a plan and preparation.

Roedd diwrnod ola'r trip ysgol wedi troi yn brofiad i'w gofio bob haf!

The last day of the school trip had turned into an experience to remember every summer!