Petcan keeps up the fire bolt attack on the nearest tentacle 

Attack: 20 Damage: 15 

The conjured dragon continues rending (twice)

Attack: 19 Damage: 15 

Attack: 25 Damage: 15 

And a breath attack DC 16 dex save for half 7 

Z continues to blast at the grappling tentacles from above:

Blast 1: Attack: 13 Damage: 6

Blast 2: Attack: 10 Damage: 10

Z uses his bonus action to try to telekinetically shove the tentacles away (forgot I had this): STR 16

(Telekinetic - Shove

As a bonus action, you can try to telekinetically shove one creature you can see within 30 ft. of you. The target must succeed on a STR save (DC 16) or be moved 5 ft. toward you or away from you. A creature can willingly fail this save.)

Flying above the deck Tempe again attacks tentacle #5 with his flame blade,  trying to get it off the ship 

Attack: 15 Damage: 16

Attack: 27 Damage: 10

Ki Attack: 22 Damage: 13

The tentacles writhe in agony and a burbling screech can be heard from below.

(Randall is up.)

Randall:

As the fifth tentacle retreats, Randall moves towards the other two on the ship, trying to place himself between them so that they both are subjected to his Spirit Guardians.  Calling down spiritual fire on the one that has the tighter grip (Tentacle 1 since it rolled the Crit grapple), Randall also sends the glowing mace of force to strike it!

Sacred Flame on Tentacle 1 (DC 17 Dexterity Save to negate):  11

Spiritual Weapon on Tentacle 1:  Attack: 28 Damage: 12

Spiritual Guardians on Tentacle 1 on its turn (DC 17 Wisdom for half):  13:

Spiritual Guardians on Tentacle 2 on its turn: (DC 17 Wisdom for half):  26:

WIS save: 22

The tentacles recoil and the mighty Octopus-like creature sinks beneath the waves.

(some things about the combat for the curious... nothing serious, just for those who like a peek behind the scenes)

Seeing the creature go down, Pepin immediately checks the bottom of the ship for any damage, before going to the surface and doing a check in the sides of the ships (he can Also walk along water due to his ring). If no structural damage is to be found he will find the rope and climb onto the deck to check on how it stands there. 

Tempe, landing stands vigilant with his flame blade in hand.. He mentally notes what he can do better next time. Then he thinks for a second remembering Bait Fish and checks to see if the creature is truly gone.

"Wow. You have to wonder how many ships have been brought down by that thing." Petcan remarks, wiping a bit of sweat from his forehead, and wiping it on a bit of sailcloth.

Zenodor similarly lands back onto the deck of the ship. "That was close. Captain, do you need our assistance for any repairs?" (Z is hoping the crew can deal with this as he has no skill in rigging sails etc)

Randall:

Brother Randall watches for the tentacles to withdraw, sending his Spiritual Weapon to harry them as they do.  He does not chase it below the waves however.

”Who is hurt?” He calls out urgently, bringing out his Holy Symbol and sending out a healing burst to save any crew that might be on the verge of death ( Channel divinity — Preserve Life).

Pepin checks the ship and luckily doesn't find any structural damage, fortunately for everyone the Octopus-thingy? was intent on sinking the ship and during it's brief attack it didn't do any serious damage, there are a few busted ropes and minor things that the crew can repair quickly. They assure the Captain that they will be underway again in a matter of minutes.

Tempe ponders strategies and tactics, and different ways to deal with threats in the future. He then decides to have Bait Fish check on the Octopus-thingy? and confirms it is returning to the depths from which it came.

Petcan remembers hearing the odd tale of a Kraken and thinks this Octopus-thingy? might well be on it's way to becoming one of those.

Zenodor is assured by the Captain and his confidence in his crew that they will be ship-shape in no time. It is in no small part to your group's efforts in fighting the Octopus-thingy? off.

Randall uses his God-given powers to save lives and this has the added benefit of bolstering the crew's morale (which helps counteract the loss of morale from just barely surviving the Octopus-thingy?).

Now that he was sure he flies out from the ship and looks for men overboard telling bait to do the same.

Perception  19

The ocean waves rise and fall as Temp does a fly-by around the ship searching for any crew unfortunate enough to have fallen overboard during the brief encounter, finding no one in dire straights is a relief.

It truly doesn't take long to get the ship underway again. Once the wind catches the sails the ship begins to pick up speed and continue to make good time on it's return trip to Laurentiis.

"Oh my, oh dear, we are fortuitous indeed to escape without any serious loss."

Mynash is relieved that no one died or was seriously hurt as a result from the incident.

Tempe lands on the ship and walks to Randall "It went to us ignored my quippier so I don't think it was merrily hungry. Maybe territorial? Or something influenced it to attack us."  

He rests 

Petcan laments. "If only these things were as easy to deal with as the purple wraiths. A song to sing it to sleep or some such... Mermaids maybe?"

Randall:

“Perhaps so, Tempe, though it might have seen the ship as a bigger source of food.  I am concerned for the next ship to pass this way, though, as we were unable to kill the tentacled horror,” responds Randall, “Still, there is nothing for it now but to continue our way onto Laurentis.”

"Our Sensa taught us that every living thing has a purpose. We must decide what ours is to be even when fate tries to intervein or till so."

He sits cross-legged to take an hour but says "So let us fight the good fight till the end." then he meditates which slowly ends up with him snoring, smoke emanating from his mouth.